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BIOLOGY 20 STUDY GUIDE
2013-2014
Holy Trinity Academy
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BIOLOGY 20
Biology 20 consists of 5 units that build on the concepts learned in Science 10. The
following outline gives a listing of the units, their major theme, approximate length of
time the unit covers in a semester, and the associated chapters in the textbook.
Unit one: Biochemistry, Photosynthesis, and Cell Respiration
Unit two: Muscles and Digestive system
Unit three: Circulatory system and Immunity
Unit four: Breathing and Excretion
Unit five: Ecology, Taxonomy, and Evolution
Evaluation
Lab reports, quizzes
Tests
Final Exam
4 weeks Ch: 5, 6
3 weeks Ch 10, 6
3 weeks Ch 8
3 weeks Ch 7, 9
5 weeks Ch: 1,2,3,4
40%
35%
25%
Student Expectations
1. Arrive to class on time and prepared
2. Raise your hand to speak. Don’t speak when someone else is speaking
3. Respect each other. Be polite in word and gesture
4. Work diligently in class and complete all homework to the best of your
ability
Academic Expectations
1. Hand in and receive a passing grade on all lab reports and quizzes
2. Receive a passing grade on all tests
3. Make up any missed work on the first day you return to school from an
absence
4. Participate actively in all class activities.
Homework Policy
1. Late assignments loose 10% until the work is returned to class. After the
assignment is returned to the class the assignment should still be completed and
handed in but will lose 50%. It is the responsibility of the student to inquire about
missed or alternate assignments.
2. Alternate assignments will be given to those who cannot do some
dissections/labs or who miss assignments with legitimate reasons.
Supplies: 2” binder, 150 pages lined loose leaf paper, 10 pages graph paper, pen, pencil,
30 cm ruler,
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Unit One: Photosynthesis and Cellular Respiration
1. describe the chemical nature of carbohydrates, fats and proteins and their enzymes, i.e.,
carbohydrases, proteases and lipases
Introduction:
The most frequently used elements in living organisms are: O, C, and H. These are used to build,
carbohydrates, proteins, lipids, nucleic acids, vitamins, and water.
Other elements used in smaller amounts include N (amino acids), Ca (bones), P (energy storage), Fe (RBC)
Na (nerve impulse and water regulation)
Water:
Property
Transparency
Description
Clear liquid
Cohesion
Molecules are ‘sticky’
Solvent
Many substances dissolve in it
Thermal
Has high heat capacity
Significance to life
Allows light to transmit through
so photosynthesis can take place
in water environments
Allows water transport in plants
and organisms to live on the
surface of rivers, ponds, lakes
Allows the transport of nutrients,
gases and wastes in organisms
and inside cells
Protects earth and ecosystems
from temp extremes, cools
organisms
Minerals: are inorganic compounds or pure elements such as, phosphorus, calcium, iodine, potassium,
sodium
Vitamins: are organic compounds that function as coenzymes in metabolic pathways
The process of digestion involves the breaking of chemical bonds that hold the carbohydrate, proteins and
fats together. This is called hydrolysis. This involves the addition of a water molecule into the
carbohydrate, protein or fat splitting the compound into two smaller compounds. The opposite process, the
building of a larger molecule from two smaller molecules by removing an H atom and an OH group from
carbohydrates, proteins, or fats, allowing them to join together, is called dehydration synthesis, or
condensation. Both processes require enzymes to make the reaction go faster.
Carbohydrates
Purpose: Store energy, structural components of cells and cell membranes
Structure: made of elements, C,H, and O
Examples: monosaccharides C6H12O6, glucose, fructose, galactose
Disaccharides C12H22O11, sucrose, maltose, lactose
Polysaccharides, glycogen, starch, wax
Of the disaccharides: Sucrose is made from glucose and fructose
Lactose is made from glucose and galactose
Maltose is made from glucose and glucose
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Lipids: Fats and Oils
Purpose: store energy, protect internal organs, make hormones, structural components of cells
Fats: produced by animals and are solid
Oils: produced by plants and animals and are liquid
Structure: triglyceride fats are made from 1 glycerol molecule and three fatty acids
Polyunsaturated fatty acids: have many double bonds between carbons, creates softer substance
Monounsaturated fatty acids: have only one double bond,
Saturated fatty acids: have no double bonds, usually solid at room temperature, harder
Cholesterol: made from fat, used to make cell membranes, and important hormones
Proteins
Proteins are made from the elements C, O, H, and N. These elements link together to make an amino acid.
There are 20 different amino acids used to make all proteins for living things on earth.
Six functions of proteins:
1) enzymes—are globular proteins, speed up reactions, ex. Amylase
2) hormones—some are also made from steroids (lipids), ex. Insulin
3) antibodies—are globular proteins that help in defense against foreign substances
4) structural proteins—are fibrous proteins, ex. Tendons, cartilage, collagen, keratin
5) transport—form part of the cell membrane and regulate what enters/leaves the cell
6) carrier—pick up various substances, attach to substances, ex. Hemoglobin
Denature- when proteins are temporarily changed by physical or chemical processes. Enzymes are
denatured by mild temperature or pH. The change is reversible.
Coagulation- when proteins are permanently changed by chemical or physical processes. If enzymes are
heated too much they with ‘melt’ or break apart; frying and egg-the egg white coagulates with heat.
2. explain enzyme action and factors influencing their action
Enzymes
 Are all made of proteins
 Are over 1000 different enzymes in the human body
 Most names of enzymes end in ase
 Function as catalysts. A catalyst speeds up chemical reactions but are not altered by the reaction
and can be used over and over again.
 They only accelerate the rates of chemical reactions that already occur, they cannot make a
reaction occur that does not occur spontaneously.
The Lock and Key Model
 The enzyme is the key and the substrate is the lock
 In order to catalyze a reaction, an enzyme must come in contact with the reactant molecules
 This compound is called the enzyme-substrate complex
 The substrate attaches to the enzyme at the active site of the enzyme
 Either the substrate is broken up (catabolism) or the substrate is attached to another substrate
(anabolism)
 Most enzymes have high substrate specificity, they will attach to only one type of compound (this
depends on the shape of the active site)
How do enzymes work?
The presence of an enzyme will speed up the reaction because the active site will facilitate the chemical
change. This happens by means of lowering the activation energy. Every reaction requires a certain
amount of activation energy. This is the energy required to break a bond (catabolism) or to make a bond
(anabolism).
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Competitive inhibitors- a molecule that is similar in shape to the substrate molecule and binds to the active
site preventing the substrate from attaching (there is competition for the active site. Ex. Inhibition of folic
acid synthesis in bacteria by the sulfonamide drugs (antibiotics)
Noncompetitive inhibitors- a molecule binds to an enzyme, but not on its active site, causing a structural
change in the enzyme which alters the shape of the active site. Ex. Heavy metals (mercury, silver) and
cyanide inhibition of any enzymes in the electron transport chain
Factors that affect enzyme activity
Temperature: increasing temp increases enzyme activity. Above the enzymes optimum temperature excess
heat will denature enzymes altering the active site rendering the enzyme inactive. Continued heating will
destroy the enzyme (heat affects any protein) (results in denaturation or coagulation)
Concentration: increasing concentration of the enzyme increases the rate of the reaction, but only small
amounts of enzyme are required because they can be reused and they work fast.
pH: when an enzyme is outside its pH range it is denatured decreasing its activity.
Inhibitors: they prevent the attachment of the substrate, hence slow down or stop the reaction.
Cofactors: are substances that attach on to the enzyme (other than the active site) to complete the enzyme
molecule and allow the enzyme to attach to the substrate Ex. Minerals in our diet. If there are no cofactors
the enzyme cannot work.
Coenzymes: are substances (vitamins) that attach on the the enzyme at the active site and allow the enzyme
to attach to the substrate. If there are no coenzymes present then the enzyme cannot work.
Tests for Carbohydrates, Proteins, and Fats
Test name
Nutrient tested for
Benedicts test
monosaccharide
Iodine test
Starch
Biurets test
Protein
Sudan IV test
Lipid, oil, fat
Translucence test
Lipid, oil, fat
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Test description
Blue to yellow, green, red, brown
Orange/yellow to blue/black
Blue to pink/purple
Pink to red
Brown to semi-clear
General Outcome 1: Students will relate photosynthesis to storage of energy in
organic compounds.
1. explain, in general terms, how pigments absorb light and transfer that energy as reducing
power in nicotinamide adenine dinucleotide phosphate (NADP), reduced nicotinamide
adenine dinucleotide phosphate (NADPH) and finally into chemical potential in adenosine
triphosphate (ATP) by chemiosmosis, describing where those processes occur in the
chloroplast
2. explain, in general terms, how the products of the light-dependent reactions, NADPH and
ATP, are used to reduce carbon in the light-independent reactions for the production of
glucose, describing where the process occurs in the chloroplast.
Photosynthesis
This process occurs in two stages:
Light dependent reaction, Photolysis, light reaction
1.
2.
3.
4.
5.
6.
7.
8.
This occurs in the thylakoid membranes inside the chloroplasts
Light is absorbed by chlorophyll ‘a’ molecules (pigments) found in clusters called photosystems
This light causes electrons in chlorophyll to be released
The released electrons are “absorbed” by chlorophyll ‘b’ molecules. The electrons are transported
from “a” to “b” through special protein carriers in the thylakoid membrane. As the electrons are
transported they lose energy. This energy is used to actively transport (by other proteins in the
membrane) hydrogen protons to the inside of the thylakoid disc. This builds up a higher concentration
of hydrogen protons inside the thylakoid. The protons will then diffuse out through another special
membrane protein that will join ADP to P to make ATP. This process is called Chemiosmosis.
The original chlorophyll a molecules are unstable and remove electrons from water molecules, splitting
water into H protons and oxygen. This is called photolysis.
The oxygen diffuses out of the cell and is released through the stomata
The H protons are added to NADP to form NADPH using electrons released by chlorophyll b.
NADP (nicotinamide adenine dinucleotide phosphate) is a transport truck that carries hydrogen
(released from water molecules) from one reaction to another in photosynthesis, from the light
dependent reaction to the light independent reaction.
Light independent reaction, Calvin Benson cycle
1.
2.
3.
4.
5.
This occurs in the stroma
Also called carbon fixation because carbon dioxide molecules are fixed into carbohydrates.
NADPH move into the stroma and release their H protons
This Hydrogen combines with other chemicals and carbon dioxide to make carbohydrates.
The energy needed to create this comes from ATP breaking down into ADP and P
Effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis
Temperature: As temperature increase the rate of photosynthesis increases, reaches a maximum, then
decline sharply as the enzymes are denatured by the increased heat.
Light intensity: as light intensity increase the rate of photosynthesis increases then reaches a maximum and
levels off
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Carbon dioxide: as Carbon dioxide levels increase the rate of photosynthesis increases, reaches a
maximum, then levels off. Only a low conc. is needed (less than 5 %) higher concentrations cause the pH
of the cell to drop which in turn could cause the enzymes to denature.
General Outcome 2: Students will explain the role of cellular respiration in releasing
energy from organic compounds.
1. explain, in general terms, how carbohydrates are oxidized by glycolysis and Krebs cycle to
produce reducing power in NADH and FADH, and chemical potential in ATP, describing
where in the cell those processes occur
2. explain, in general terms, how chemiosmosis converts the reducing power of NADH and
FADH to the chemical potential of ATP, describing where in the mitochondria the process
occurs
3. distinguish, in general terms, between animal and plant fermentation and aerobic
respiration
4. summarize and explain the role of ATP in cell metabolism
5. identifying factors affecting the rate of cellular respiration
Carbohydrate Metabolism, Glucose Metabolism, Cellular Respiration
Where does glucose come from and how does it get into the cells?
1. Polysaccharides and disaccharides are broken down to monosaccharides (glucose, fructose, and
galactose.
2. These nutrients are absorbed into the blood and brought to the liver
3. The liver converts fructose and galactose into glucose. It also regulates blood glucose levels.
4. The cells absorb glucose from the blood (capillaries)
The processes that go on inside the cell (actual cell respiration)
Cellular respiration is the process where food energy, or more specifically the chemical bonds inside
glucose, is converted into chemical bonds that make A.T.P. The overall reaction is as follows:
1 glucose
+
6 oxygen
6
carbon dioxide
+ 6 water
+ 36 A. T. P. + waste heat
ATP—is adenosine triphosphate. This molecule store significant amounts of energy in the bond that holds
the last phosphate.
The processes (reactions) that occur to break down glucose involve oxidation and reduction reactions.
Oxidation—the removal of hydrogen atoms from a molecule. The hydrogen are picked up by molecules
called coenzymes.
Reduction---the addition of hydrogen atoms to another molecule. The coenzymes add the hydrogen atoms
to other molecules.
N.A.D.—nicotinamide adenine dinucleotide—a coenzyme that picks up hydrogen atoms (analagous to an
empty dump truck). When it picks up hydrogen it becomes N.A.D.H ( the full dump truck)
F.A.D.---Flavin adenine dinucleotide—another conezyme that picks up hydrogen atoms. It becomes FADH
Reduction always follows oxidation, with the use of enzymes and coenzymes
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The Fate of Glucose
If not needed:
1. glucose is converted to glycogen, stored in the liver and muscle cells
2. if glycogen storage space is filled glucose is stored as fat
3. if glucose cannot be stored or concentrations of glucose are too high it is excreted by the kidney
If needed:
1. glucose is absorbed by the cells, is oxidized, and the energy released is stored in A.T.P. or given off as
body heat
Glucose oxidation – occurs in 3 stages:
1 glycolysis—does not need oxygen
2. citric acid cycle, or Krebs cycle
3. electron transport chain
(stages 2 and 3 will only occur in the presence of oxygen.
Glycolysis
1. occurs in the cytoplasm
2. does not use oxygen
3. splits one glucose (6carbon) into 2 pyruvic acid (3carbon)
4. produces 2 pyruvic acid, 2 NADH , 4ATP
5. uses 2 ATP to phosphorylate glucose. This prevents glucose from diffusing out of the cell as well as
makes glucose more reactive
Fate of Pyruvic Acid
1. if no oxygen—pyruvic acid will be converted to lactic acid. This step uses NADH . This is called
anaerobic respiration in animal cells. The lactic acid lowers pH and prevents muscle contractions. This
process also occurs in some yeast cells producing alcohol instead of lactic acid as an end product, called
alcoholic fermentation.
2. If oxygen is present pyruvic acid enters Krebs cycle. This occurs inside the mitochondria
Anaerobic Respiration (glucose  lactic acid or alcohol) (fermentation)
1. occurs in muscle cells during strenuous exercise, when the cell uses oxygen faster than the circulatory
system can provide it.
2. Not all cells in the body do this, i.e. brain cells die without oxygen
3. Lactic acid decreases pH, muscles cannot contract when pH gets to low
4. Muscle fatigue is overcome when the oxygen debt has been met by increased breathing and heart rate
increasing the supply of oxygen to the muscle cells
5. Lactic acid is removed from cells and converted to glycogen in the liver
6. Net ATP produced is 2.
Aerobic Respiration
1. uses oxygen
2. occurs in any cell that has mitochondria
3. occurs in 3 stages:
a. glycolysis
b. krebs cycle
c. electron transport chain
(both b and c occur inside the mitochondria)
Mitochondria anatomy
Cristae: folded membranes inside the mitochondria, where the electron transport chain is found
Matrix: fluid inside the mitochondria surrounding the cristae, where krebs cycle occurs
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Glycolysis
1. once pyruvic acid is formed it enters the mitochondria
2. when inside the mitochondria the pyruvic acid (3carbon) is converted into a new 2carbon compound
called acetyl coenzyme A. For this to occur carbon dioxide is removed (decarboxylation) as well as
hydrogen from NADH. This is called the “link reaction”.
Krebs cycle
1. is a cyclical process where acetyl coenzyme A is added to a 4 carbon compound to make a 6 carbon
compound. This 6 carbon compound is then broken down into the original 4 carbon compound. In the
process 2 carbon dioxide molecules are removed as well as NADH and FADH
2. for every one glucose molecule this cycle occurs twice.
3. This occurs in the matrix
Electron Transport Chain
1. is a series of oxidation reduction reactions that occur on the cristae
2. hydrogen electrons are transferred from one electron acceptor (cytochrome) on the cristae to another
releasing energy. The energy released is used to actively transport hydrogen protons to the space
between the cristae and the outer mitochondrial membrane (called the intermembrane space)
3. as hydrogen difuse back across the cristae ATP is produced (chemiosmosis)
4. The last electron acceptor is the strongest, oxygen, forming water
5. If the cell lacks oxygen the E.T.C. does not function which prevents Krebs cycle from working.
6. NADH drops its hydrogen at the first cytochrome, producing 3 ATP
7. FADH drops its hydrogen at the second cytochrome, producing 2ATP
8. NAD and FAD can go back to Krebs cycle to pick up more hydrogen
Other metabolic pathways/other sources of fuel for cell respiration
1.
2.
Fats/lipids—are broken down into fatty acids and glycerol. Fatty acids enter krebs cycle and glycerol
enters glycolysis
Proteins—are broken down into amino acids. These may enter glycolysis or krebs cycle
Effect of pollutants: cyanide and hydrogen sulfide
These block enzymes in the electron transport chain, shutting down ATP production
Uses of ATP: muscle contractions, protein synthesis, nerve impulses, active transport
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Unit 2: Human Systems: Muscles and Digestion
General Outcome 1: Students will explain the role of the motor system in the
function of other body systems.
1.explain how the motor system supports body functions, i.e., circulatory, respiratory,
digestive, excretory and locomotory
Muscles are part of blood vessels and the heart, used expand our thoracic cavity to help us breath, form the
digestive tract moving our food along, and control the flow of urine out of the body. But muscle are most
recognized for movement, allowing us to move and carry things in our environment.
Muscular System
Body System
Circulatory
Digestive
Respiratory
skeletal
Muscle type
Smooth
cardiac
Smooth
smooth
Striated
Function of muscles
Maintain pressure in arteries
Composes the heart
peristalsis
Change thoracic volume
Body movement
2. describe, in general, the action of actin and myosin in muscle contraction and heat
production.
Muscle
Muscle fiber: the muscle cell
Myofibril: bundles of proteins found inside the muscle cell
Sarcomere: the contracting unit in the myofibril
Actin: thin protein filaments attached to Z band of the sarcomere
Myosin: the thick protein filaments found suspended between actin filaments; not attached to z band
Sliding filament theory: Actin filaments slide over the myosin by making attachements to the myosin. This
causes the sarcomere to shorten causing the muscle cell and the muscle to shorten
Steroid effects on muscles
Steroids cause increase building of the protein filaments (actin and myosin), with a resulting increase in
muscle strength and bulk. They allow muscle cells to repair themselves faster after excrecise. Exercise
causes tiny tears in the proteins of the myofibrils. Steroids rebuild these proteins faster than normal.
Creatine phosphate: an alternative energy source for muscle contraction; used after ATP.
3. explain that the goal of technology is to provide solutions to practical problems
• identify specific pathologies of the motor system and the technology used to treat the
conditions.
Pathologies:
Muscle cramp: a sustained, uncontrolled, maximum muscle contraction
Muscle fatique: the inability of the muscle to contract produced by a lack of ATP and buildup of lactic acid.
Lactic acid lowers the pH of the cell preventing attachement of actin and myosin.
Paralysis: inability of the muscle to contract. Quadrapalegic= 4 limbs cannot move, parapalegic= 2 limbs
cannot move
Muscular dystrophy: hereditary disease characterized by progressive wasting of muscles.
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General Outcome 2: Students will explain how the human digestive exchange energy
and matter with the environment.
1. identify the principal structures of the digestive system, i.e.,
• mouth, esophagus, stomach, sphincters, small and large intestines, liver, pancreas, gall
bladder
2. describe the chemical and physical processing of matter through the digestive system into
the bloodstream
The digestive system involves four processes:
Ingestion: the intake of food
Digestion: the breakdown of food into smaller pieces
Absorption: the movement of food molecules from the digestive tract across membranes into the blood
Egestion: the removal of the undigested waste remain of food from the body
The process of digestion occurs by two mechanisms:
Physical digestion: the mechanical breakdown of food into smaller pieces. This makes the food easier to
swallow, but also increases the surface area for enzyme digestive action later.
Chemical digestion: The chemical breakdown of food from large macromolecules into smaller molecules
that can be absorbed across and through membranes into the blood.
Anatomy of the Digestive System
1. The Mouth
The mouth has several functions in digestion:
a. Ingestion: the mouth is the point of entry for all food. The back of the mouth is connected to a
common opening for both the digestive and respiratory systems, the pharynx. The pharynx is
connected to the esophagus. The esophagus moves a bolus of food to the stomach by rhythmic
contractions of muscles called peristalsis.
b. Physical digestion: the mouth contains teeth, which are used to cut and grind food into smaller pieces.
It addition saliva is added, containing water, which dissolves many substances, and makes food easier
to swallow and taste. Each type of tooth has a specific function:
Type of tooth
Incisors
Canine
Premolars
molars
c.
d.
Number in mouth
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4
8
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Function
Cut food into pieces to swallow
Cut and hold food
Grind food
Grind food
chemical digestion: The mouth contains saliva glands below the tongue and above the roof of the
mouth. Saliva contains water and the enzyme salivary amylase. This enzyme digestions starch into
disaccharide’s. The water in saliva also makes food easier to swallow and easier to taste.
Absorption: very little absorption happens in the mouth. Food does not stay in the mouth long enough
to be absorbed, nor are the food molecules digested small enough to pass through the lining of the
mouth into the blood. Some molecules that do not require digestion do pass through the lining of the
mouth (alcohol, water, some drugs) but since they are not in the mouth that long not much absorption
happens.
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2. The Stomach
The stomach is a muscular organ that is involved in the physical and chemical digestion of food, and the
absorption of some nutrients into the blood. Its primary function, however, is the physical and chemical
breakdown of proteins.
Valves control the entry and exit of food into the stomach. These valves (also called sphincters) are
circular muscles with hole in the middle. Contraction of the valve closes the hole, while relaxation opens it
allowing food the pass through. There are two valves, one on the bottom of the esophagus, the cardiac
valve, and one and the beginning of the small intestine the pyloric valve. The cardiac valve controls food
entry while the pyloric valve controls food exit.
The stomach is a stretchable bag that can expand as it receives food. The inside lining has many wrinkles,
called gastric rugae, that stretch out, much like an accordion, as more food enters.
The inside lining of the stomach also contains many clusters of cells called gastric glands. These cells
produce the proteins pepsinogen and lipase. Other clusters of cells produce hydrochloric acid. When the
pepsinogen is released it will mix with released HCl forming the enzyme pepsin. Pepsin digests large
proteins (polypeptides) into smaller chain polypeptides, to be later digested in the small intestine.
Pepsinogen is stored in an inactive form so that it does not digest the stomach itself, which is made of
protein (an ulcer would result).
The lining also contains cells that secrete mucus. The mucus provides protection against the corrosive
action of HCl as well as the digestive action of pepsin.
Small amounts of gastric lipase are also produced in the stomach. These begin the initial breakdown of fats
and oils.
The mixture of food and digestive fluids in the stomach is now called chyme.
3. The Small Intestine
The small intestine has two major functions. First, to complete the chemical digestion of all the
macronutrients, and second, to absorb the end products of chemical digestion into the blood stream.
The small intestine is divided into three sections. The first 20-50 cm is called the duodenum, then the
jejunum and ileum. The duodenum is where the chyme from the stomach and fluids from the pancreas and
gall bladder mix together. Afterwards this mixture slowly moves down the jejunum and ileum, all the
while chemical digestion and absorption are occurring. The inner lining of the small intestine secretes
digestive enzymes that break down disaccharides, and polypeptides (proteins).
The surface area of the small intestine has been modified in three ways to enhance absorption:
First, the inner lining has many wrinkles that increase surface area about 3 times.
Second, the inner lining has millions of finger-like projections called villi, that increase surface area a
further 10 times. Inside the villi are blood vessels to which the end products of digestion travel. It is across
the lining of the villi that absorption (by diffusion and active transport) of nutrients occurs.
Third, the lining of the villi has many wrinkles on its surface called micorvilli. The microvilli enhance
surface area a further 20 times. Altogether all three adaptations increase the surface area of the small
intestine by 600 times.
The enzymes produced by the small intestine are made by the cells that line the villi. Under the microscope
these projections or wrinkles of the lining of the villi look like a brush. Hence, the enzymes are often
referred to as “brush border enzymes”, these include maltose, sucrose, lactose, and peptidase.
4. The Large Intestine
The large intestine is divided into three segments. The ascending colon, transverse colon, and descending
colon. The rectum is a storage organ for feces found immediately after the descending colon. A valve, the
ileocaecal valve, controls the movement of material from the ileum into the caecum. The caecum is the
pouch at the beginning of the large intestine (ascending colon) that receives material from the ileum.
Attached to the caecum is the appendix. The appendix has no function in digestion. It may serve as a
storage organ for bacteria that are important in the large intestine.
The large intestine is not involved in either physical or chemical digestion of food. Its major purpose is to
reabsorb water from the waste material back into the blood. This is where fiber in the diet is important.
Fiber, which is the undigestable portion of plant material (primarily cellulose, which we do not have
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enzymes to digest), helps to hold onto water in the large intestine. A diet high in fiber ensures enough
water will remain in the feces for regular bowel movements. A low fiber diet results in too little water in
the feces and constipation.
The large intestine also contains large amounts of bacteria. The bacteria help to break down some nutrients
to make vitamin K, which then is absorbed into the blood stream along with water.
5. The Pancreas
The pancreas provides two functions: it produces digestive enzymes and a buffer, and regulates blood
sugar.
The pancreas functions both as an endocrine and exocrine gland. Endocrine glands produce hormones that
are released into the blood stream. Exocrine glands produce fluids released into tubes that travel to another
body region. In digestion the pancreas produces many digestive enzymes (see chart) that are released into
the pancreatic duct, travel to the duodenum, and continue the chemical digestion of the macronutrients.
The pancreas also produces a buffer, sodium bicarbonate, that neutralizes the acidic chyme that enters the
duodenum from the stomach. This helps the enzymes work better and prevents pepsin from digesting the
lining of the small intestine.
The endocrine function of the pancreas is to produce two hormones. The hormones are produced in tiny
clusters of cells called the Islets of Langerhans. There are two types of cells. The Beta cells produce
insulin and the alpha cells produce glucagon. Insulin is produced when blood sugar increases (after a meal)
and helps to make muscle and liver cells more permeable to glucose (blood sugar) while also converting
glucose into a large polysaccharide, glycogen, in the muscle and liver cells. When blood sugar falls below
normal levels the alpha cells produce glucagon which has the opposite effect. This prevents glucose from
entering the cells and cause glycogen to be converted into glucose, increasing blood sugar.
6.
The Liver
The liver has many functions. In digestion its main function is to produce bile. Bile causes the physical
breakdown of fat and oil into smaller droplets. This is called emulsification. The bile is produced in the
liver but stored in the gall bladder. A small tube carries the bile from the liver to the gall bladder. Then the
gall bladder, when stimulated, releases the bile into the common bile duct which travels to the duodenum.
The liver also helps to detoxify the blood, breaking down drugs and other toxic chemicals, as well as the
breakdown of dead red blood cells, and the breakdown of excess amino acids (deamination).
As discussed in the pancreas, the liver is also involved in the regulation of blood sugar. It responds to
insulin and glucagon to either store or release glucose.
The liver also makes blood clotting proteins (fibrinogen), and helps in calcium uptake from the blood.
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Dead red blood cells
Enter liver
Hemoglobin
Iron
Into the blood
cells
Heme group
globin group
amino acids
Bilirubin
amino acids
deamination or protein synthesis
into the blood
To bone marrow to hepatocytes
into the blood
deamination or protein synthesis
Bile
urea
Bile duct
Gall bladder
Enzyme chart
Digestive fluid
Saliva
Gastric juice
Location
Mouth
Stomach lining
Intestinal juice
Epithelial cells of the villi
Pancreatic juice
Pancreas
Bile
Liver
Enzyme
Salivary amylase
Pepsin (pepsingen and
HCl)
Rennin
Gastric lipase
Sucrase
Maltase
Lactase
Peptidase
Trypsin
Amylase
Lipase
Nuclease
No enzymes
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Function of enzyme
Starch to dissacharides
Proteins to amino acids
Coagulates milk
Fats to fatty acids and
glycerol
Sucrose to G. and F.
Maltose to G.and G.
Lactose to G.and Ga
Proteins to Amino acids
Proteins to Amino acids
Disacch to monosacch
Fats to F.A. and glycer.
Breaks apart DNA
Emulsifies fat
Control of Digestive Secretions
All digestive enzymes in humans are produced in special cells. The appropriate enzyme is produced only
when certain cells are stimulated. Stimulation may be provided by hormones, nerve impulses, peristalsis,
or a combination of these.
Digestive juice
Saliva
Gastric juice
Intestinal juice
Pancreatic juice
Bile
Control
nervous-sight, smell, sound, thoughts
nervous, hormonal, peristalsis
peristalsis
hormonal
hormonal
Control of Gastric juice
1.Peristalsis of the stomach muscles causes the release of gastric juice from the inside lining of the
stomach.
2.Thoughts of food result in nerve impulses sent to the stomach (by the vagus nerve) which bring about the
release of gastric juice
3.Peristalsis in the stomach causes the release of a hormone, gastrin, (from special cells in the stomach) into
the blood. This hormone stimulates the production and release of gastric juice.
Control of Pancreatic Juice
When food enters the duodenum its low pH causes the release of hormones from the small intestine. The
hormones released, secretin and pancreozymin, stimulate the production and release of pancreatic juice.
Secretin causes the release of sodium bicarbonate, and pancreozymin causes the release of the pancreatic
enzymes.
Control of bile
When fatty food enters the duodenum the cells of the small intestine release another hormone,
cholecystokinin. This hormone causes the gall bladder to contract, emptying its contents, bile, into the
duodenum.
5. explain that the goal of technology is to provide solutions to practical problems
• discuss and evaluate the role of food additives and/or food treatment to solve the
problems of food spoilage, e.g., antioxidants, irradiation technology
• explain the biological basis of nutritional deficiencies, including that of anorexia
nervosa, and the technological means available to restore equilibrium of body systems
• identify specific pathologies of the digestive system and the
technology used to treat the conditions
Disorders of the Digestive system
Heartburn: the irritation of the lower esophagus by gastric fluids squeezing through the cardiac valve
Indigestion: inadequate digestion of food, either too much gastric juice or too little gastric juice
Ulcers: a lesion on the inner lining of the stomach caused by gastric juice or bacteria
Hernia: the protrusion of a part or structure through the tissues normally containing it.
Hemorrhoids: the swelling of the veins surrounding the anus causing a protrusion
Appendicitus: the swelling of the appendix by bacterial infection
Peritonitus: the infection of the inner lining of the abdominal cavity (peritoneum) due to rupture of the
appendix
Diarrhea: condition produced when too much water remains in the feces
Constipation: condition produced when too little water remains in the feces
Anorexia nervosa: a psychological and endocrine disorder primarily in young women in their teens that is
characterized by a pathological fear of weight gain, leading to faulty eating patterns, malnutrition and
excessive weight loss.
15
Unit 3: Human Systems: Circulation and Immunity to Disease
General Outcome 1 : Students will explain the role of the circulatory and defense
systems in maintaining an internal equilibrium.
1. describe the structure and function of blood vessels; i.e., arteries, veins, and capillaries
2. explain the role of blood in regulating body temperature
3. explain the role of the circulatory system at the capillary level in aiding the digestive,
excretory, respiratory and motor systems’ exchange of energy and matter with the environment
4. describe and explain, in general terms, the function of the lymphatic system
Delivers gases to and from body cells, nutrients to body cells, wastes away from body cells. Helps
thermoregulate the body and delivers blood clotting and immune cells to help prevent disease and provide
protection from the environment
Open system- allows blood cells to leave the vessels and pool in a collecting area of the body
Closed system- blood cells never leave the vessels
Composed of three components:
1. Blood vessels: arteries, veins, and capillaries
2. Pump: the heart
3. Blood: water, red blood cells, white blood cells, platelets
Blood vessels
1. Arteries
-Carry blood away from the heart
-Have thicker muscles in their walls
-Have higher pressure
-Carry oxygenated blood except in one case
2. Veins
-Carry blood to the heart
-Have thin muscles in their walls
-Have low pressure
-Have valves that prevent the back flow of blood. The valves prevent the blood from pooling in the lower
extremities. Skeletal muscle contractions also help to push the blood in veins to ensure an adequate
volume returns to the heart.
-Carry deoxygenated blood except in one case
3. Capillaries
-Connect arteries and veins
-Have very thin walls to allow for the exchange of gases, water, nutrients and wastes between body cells
and the blood. Some white blood cells can also pass through the capillary walls.
-The pressure drops from medium to low as it passes through the capillaries
-Have circular muscles around the arteriole end to regulate the flow of blood through capillaries. This is
called vasoconstriction and vasodilation. In the skin this helps to conserve heat or increase heat loss
respectively.
-They are the most numerous type of vessel.
The lymphatic system
Is a system to accessory vessels throughout the body that empty into the superior vena cava, and lymph
nodes, lymph, the spleen and thymus gland.
The lymphoid organs have specific functions that assist immunity:
Lymph nodes: clean lymph Spleen: cleans the blood Thymus: where T lymphocytes mature
16
4. identify the principal structures of the heart and associated blood vessels, i.e., atria,
ventricles, septa, valves, aorta, vena cavae, pulmonary arteries and veins, sinoatrial node
5. describe the action of the heart and the general circulation of the blood through coronary,
pulmonary and systemic pathways
The Heart
Pericardium: a thin membrane sac that surrounds the heart. This helps reduce friction between the heart
and lungs and chest cavity.
Atria: the receiving chambers of the heart, they are smaller and made of less muscle, they collect blood and
pump it to the ventricles
Ventricles: are the major pumps of the heart, they receive blood from the atria and pump it to all body parts
Valves: are found in the major arteries leaving the heart and between the atria and ventricles. They prevent
the back flow of blood
Right atrium: receives deoxygenated blood from vena cavas
Left atrium: receives oxygenated blood from pulmonary vein
Right ventricle: pumps deoxygenated blood to lungs
Left ventricle: pumps deoxygenated blood to body parts
Aortic semilunar valve: prevents back flow of blood into the left ventricle
Pulmonary semilunar valve: prevents back flow of blood into right ventricle
Tricuspid valve: prevents back flow of blood into right atrium
Bicuspid valve: prevents back flow of blood into left atrium
Inferior vena cava: brings deoxygenated blood from below shoulders to right atrium
Superior vena cava: brings deoxygenated blood from above shoulder and above to right atrium
Pulmonary vein: brings oxygenated blood to the left atrium from the lungs
Pulmonary artery: brings deoxygenated blood to the lungs from the right ventricle
Dorsal aorta: brings oxygenated blood from left ventricle to all body parts
Blood flow through the heart
Superior and inferior vena cava-----right atrium----tricuspid valve----right ventricle----pulmonary semilunar
valve----pulmonary artery----lungs----pulmonary vein----left atrium----bicuspid valve----left ventricle----aortic semilunar valve----dorsal aorta----body parts.
The right side of the heart always has deoxygenated blood, while the left side of the heart always has
oxygenated blood. The atria always contract simultaneously while the ventricles relax, and when the atria
relax the ventricles contract simultaneously.
Regulation of Heart beat
The heart has a built in conduction system.
The sinoatrial (s-a) node starts each cardiac cycle; it sets the pace for the heart (called the pacemaker). It is
located in the upper right corner of the right atrium. It causes the contraction of the atria and stimulates the
a-v node. The a-v node (atrioventricular node) stimulated the muscles of the ventricles to contract through
a large nerve called the purkinje fibers
An electrocardiogram is a print out of the electrical activity of the heart; the activity of the s-a and a-v
nodes.
Heart Sounds
The heart beat consists of two sounds. The first sound is caused by the closing of the bicuspid and tricuspid
valves. When blood pushed by the ventricles hits these valves they close and the blood hitting them makes
a sound. The second sound is caused by the closing of the semilunar valves. When the ventricles relax
blood in the pulmonary artery and aorta start to move backwards into the ventricles. The blood hits these
valves causing them to close, making a sound.
A stethoscope is an instrument used to listen to the heart sounds
17
Blood Pressure
Blood pressure is created both when the ventricles contract and relax. It is a measure of the force of the
blood in the blood vessels. Higher pressure results when the ventricles contract (systolic pressure). A
lower pressure results when the ventricles are relaxed, not pumping (diastolic pressure). Pressure is
recorded as a fraction with units in mm of Hg: 120/80. The upper number is the systolic pressure while the
bottom number is the diastolic pressure.
Factors that influence blood pressure include: amount of blood in the body, pulse, size of artery, viscosity
of the blood, distance from the heart, stress, diet, genetics.
A sphymomanometer is an instrument that measures blood pressure
Cardiac output
A measure of the amount of blood the heart pumps out during a given time interval. The average heart
pumps out about 70 ml of blood each beat (volume from the left ventricle).
Pulse
The surge of blood through an artery created when the left ventricle contracts.
Disorders-Pathologies
Heart attack: increased activity of the heart often due to an area of the heart (muscle group) that is not
working or has even died.
Artheriosclerosis: hardening of the arteries. This decreases the inner diameter of an artery increasing
resistance to blood flow, increasing blood pressure. The plague can also cause platelets to release their
clotting factors causing the formation of a blood clot (thrombosis) around the plaque. This clot may
dislodge travel with the blood further down the artery and lodge in smaller arteries depriving the tissues
that was supplied by this artery of oxygen. If this happens in heart tissue it places a strain on the heart
decreasing heart muscle lifespan. This may lead to a heart attack especially if the artery is the one taking
blood to the heart muscles themselves. If the heart muscles are deprived of blood (and oxygen) they will
eventually die leading to the rest of the heart beating faster and harder to compensate for the loss of muscle.
This often leads to a heart attack.
Stroke. This occurs when a blood vessel in a part of the brain ruptures, or a clot (thrombosis) forms in a
vessel in the brain causing part of the brain to not get oxygen and those cells die.
Varicose veins. This occurs when the veins remain dilated or stretched out and the valves do not close
properly allowing the blood to pool in the vein , usually in the legs.
Aneurism The dilation of an artery
Technologies
Artificial valves: mechanical valves of metal cages and plastic balls to replace natural (defective) valves
Bypass surgery: sewing an artery around a plaque buildup in the coronary artery of the heart
Shunt: a metal cage placed in an artery to keep it open, or to open it up wider
Dyes: are used to highlight blood flow through the coronary artery and identify blockages
Pacemaker: an electronic device to control the s-a node.
Angioplasty: inserting a tiny tube with a tiny balloon on the end into a blocked artery and expanding the
balloon to open up the artery
Artifical heart: a mechanical pump to take the place of the natural heart
Xenotransplants: placing the organ of another animal into humans, ex. Baboon and human heart transplants
18
6. describe the main components of blood and their role in transport and in resisting the
influence of pathogens; i.e., erythrocytes, leucocytes, platelets, plasma
7. list the main cellular and non-cellular components of the human defense system and
describe their role, i.e., skin, macrophage, helper T cell, B cell, killer T cell, suppressor T
cell, memory T cell.
The Blood: composed of 55% plasma and 45% cells
Plasma: mostly water, has dissolved nutrients, wastes, gases, hormones, and other special proteins
Red blood cells -- Erythrocytes
-formed in the bone marrow
-have no nucleus
-live about 120 days
-broken down in spleen and liver
-contain the chemical hemoglobin which has a strong attraction for oxygen
-stay in vessels, leave only if vessel is damaged
-shaped like a bagel; this decreases the size of the cell (so they can fit through the capillaries) yet maintains
surface area (for efficient gas exchange)
-the lower the oxygen concentration in the air the greater the rbc production by the bone marrow
-there are 4 major blood types determined by protein markers on the rbc (type A,B, AB, O)
Blood types and transfusions
ABO group: this consists of specific proteins (antigens) found on the red blood cell membrane. You can
have either A or B or both proteins. The absence of both proteins means you have type O blood
RH group: the rhesus factor, another protein on the red blood cell membrane. Rh positive means you have
this protein, RH negative means you do not have the protein
Type
A
B
AB
O
Antigen
A
B
AB
Neither
antibody
B
A
Neither
A and B
Blood type matching
Receivers blood (antibodies in brackets)
Donors blood
A
B
AB
O
A(B)
Match
Agglutinate
Agglutinate
Match
B(A)
Agglutinate
Match
Agglutinate
Match
AB(NEITHER)
Match
Match
Match
Match
O(AB)
Agglutinate
Agglutinate
Agglutinate
Match
Always consider the antibodies in the receivers’ blood and the proteins in the donors’ blood to determine is
a match will occur. The antibodies in the receivers’ blood with attack the proteins in the donors’ blood.
Type O blood is called the universal donor because it contains neither A or B protein, while type AB blood
is called the universal receiver because it contains no antibodies to A or B blood.
RH factor: is another protein (antigen) found on the cell membrane of rbc’s. If you have this protein you
are RH positive and cannot produce antibodies to the RH factor, if you donot have this protein you are RH
19
negative and can produce antibodies to the RH factor. Therefore a person who is RH negative cannot
receive RH positive blood, but someone who is RH positive can receive RH negative blood.
White blood cells -- Leukocytes
-produced in the bone marrow, can leave the blood vessels through the capillary walls
-have a nucleus
-lifespan varies with what they are exposed to
-one wbc for every 600 rbc
-fight infections directly by phagocytosis
-fight infections inderectly by producing antibodies
-high wbc count can mean the body is fighting an infection, there are other explanations for high wbc
-pus is destroyed wbc, bacteria, and interstitial fluid
B cells – cause antibodies to be made
Helper T cell- stimulates B cells to make antibodies and killer T cells to work
Killer T cell- kills infected cells and cancer cells
Suppressor T cell- shuts down immune response
Memory T cell- a clone of long lived lymphocytes that remain in the lymph node until activated by
exposure to the same antigen that triggered its formation. They will stimulate B cells to produce
antibodies
Antibodies- a protein produced by B cells that bring about an effect on the pathogen/antigen
Histamines: are released by special white blood cells (basophils) and cause both dilation and increased
permeability of nearby capillaries
Platelets -- thrombocytes
-produced in the bone marrow
-are fragments of cells that contain blood clotting proteins (factors, specifically
Thromboplastin/thrombokinase)
Disorders of the circulatory system: Pathologies
Anemia: lack of red blood cells, due to lack of iron (iron is needed to make hemoglobin), characterized by
general continuous tired feeling.
Hemophilia: lack of the ability of the blood to clot, due to low platelets, or lack of a blood clotting factor
(protein)
Bacterial infection: indicated by increased white blood cell count
Mononucleosis: the presence of abnormally large number white blood cells in the blood. This reduces red
blood cell numbers causing lack of oxygen and fatigue associated with this disease.
Technologies
Vaccinations: provide immunity to severe diseases but in some cases can cause harmful, lethal side effects
Blood transfusions: Add blood from a different person to another.
Blood testing: taking small sample of blood and testing for gases, drugs, hormones, or other substances.
20
Pathogen infection
Skin and mucous membranes
Blood clot (thrombosis)
Phagocytosis by monocytes (macrophage) and neutrophils
Mast cells release histamine
To thymus gland
to lymph nodes
Clonal selection
clonal selection
Lymphoctes + lymphokine
Helper T cells
Clonal expansion
Memory
T cells
Killer
T cells
suppressor
T cells
B cells
Helper
T cells
clonal expansion
Memory
B cells
Plasma
cells
Produce
Antibodies
Attach to
Antigens
21
Unit 4: Human Systems: Excretion and Breathing
General Outcome 1: Students will explain the role of the excretory system in
maintaining an internal equilibrium in humans through the exchange of energy and
matter with the environment.
1. identify the principal structures of the excretory system, i.e., kidneys, ureters, urinary
bladder, urethra
• observing the principal features of a mammalian excretory system and identifying
structures from drawings obtained from various print and electronic sources
2. describe the function of the kidney in excreting metabolic wastes and expelling them into
the environment.
Purpose of excretion
Excretion involves any process which removes metabolic wastes from the body.
Animal waste includes urea, uric acid and ammonia, Plant waste includes CO2, H2O and O2
This is performed by the skin, lungs, large intestine/rectum, and kidneys (organs of excretion).
The major organ of excretion is the kidney.
The kidney is also involved in regulating water concentration of the blood. (osmoregulation)
The kidney also maintains the acid base balance in our bodies by regulating the H ion conc.
The major waste product in the blood is urea. Urea is produced by the liver in a process called deamination
Deamination involves the breakdown of amino acids, and occurs in the liver. Amino acids are broken
down into the amine group and a carboxylic acid. The carboxylic acid can be used in cellular respiration.
The amine group is combined with another hydrogen atom to make ammonia. Then, since ammonia is very
toxic to body cells it is converted to a less toxic compound, urea, by the addition of carbon dioxide. Also
several urea molecules can be combined to form uric acid. The liver dumps urea and uric acid in to the
blood. The kidneys filter these wastes from the blood and produce urine.
Organ
Lungs
Skin
Intestine
Kidneys
Excretory substance
Carbon dioxide, water
Water, urea, salts
Undigested material, bile
Water, salts, urea, uric acid
Excretory system anatomy
Kidney: primary function is to remove nitrogenous waste from the blood, see other functions above.
Renal artery: brings blood in high pressure and high nitrogen waste to the kidney
Renal vein: takes cleaned blood away from the kidney back to the inferior vena cava
Ureter: takes urine from kidney to urinary bladder
Urethra: takes urine from bladder to outside environment
Urinary bladder: hold urine in the body
Kidney anatomy
Renal cortex: the outermost layer of the kidney where the filtering unit, the nephron, is found
Renal medulla: the middle region of the kidney. It is composed of arteries and veins, bringing blood to and
from the cortex nephron, and tubules that carry urine from the nephron to the central core of the kidney
Renal pelvis: The hollow central core of the kidney. Urine from all the nephrons drains into this area. The
pelvis exists the kidney through the ureter.
Nephron: the microscopic filtering unit of the kidney. There are approximately 500,000 of theses in each
kidney
22
3. explain the structure and function of the nephron in maintaining normal body fluid
composition, i.e., water, pH, ions
Nephron anatomy
Afferent arteriole: brings blood into the glomerulus
Glomerulus: filters the blood, it allows a portion of the plasma to escape but retains the large red blood
cells and large proteins. The plasma that leaves the glomerulus is called the filtrate. It contains tiny pores
that only allow small molecules to leave (fenestrated capillaries)
Efferent arteriole: brings blood out of the glomerulus and branches to form the capillary net
Capillary net: surrounds the nephron and absorbs water, ions, and nutrients from the tubules
Bowman’s capsule: collects the filtered plasma (filtrate) from the glomerulus
Proximal convoluted tubule: filtrate from Bowman’s capsule travels through this tube. Ions, nutrients and
water are removed from the filtrate and move back into the blood in the capillary net.
Distal convoluted tubule: the last section of the nephron. This makes the final adjustment to water in the
urine. It is affected by ADH. ADH increases the permeability of the DCT to water, consequently more
water travels out of the DCT back into the blood in the capillary net.
Loop of Henle: extends from the renal cortex into the renal medulla. As it extends into the medulla region
the medulla region gets saltier due to the active transport of sodium out of the filtrate. This helps to draw
out water. But the ascending loop of Henle is impermeable to water. Still sodium is being actively
transported out of the ascending loop. This makes the urine hypotonic while the medulla region is
hypertonic.
Collecting duct: the DCT of each nephron connects to this tube. The collecting ducts all connect together
internally at the hollow renal pelvis. Urine from each nephron flows into the collecting duct and then to the
renal pelvis.
Processes that occur in the nephron
1. Filtration
Sometimes also called force filtration. The blood pressure in the glomerulus forces about 20% of the blood
out into Bowman’s capsule. About 600 ml of blood flows through the kidney each minute. About 120 ml
fluid each minute is forced into Bowman’s capsule. Red blood cells, plasma proteins, and platelets are too
large to pass through the glomerulus into Bowman’s capsule.
2. Reabsorption
Only 1ml of the 120 ml will form urine. The rest is reabsorbed by different sections of the nephron.
Selective reabsorption by both active and passive transports moves the particles and water back into the
blood in the capillary net. First sodium ions, glucose and amino acids are active transported from the
filtrate into the blood. This requires ATP provided by mitochondria. Then negative ions (chloride and
bicarbonate) follow by charge attraction. The build up of all these particles in the blood and renal medulla
creates a hypertonic blood compared to the filtrate (which is now hypotonic). This concentration is highest
at the tip of the loop of Henle which is in the center of the renal medulla region of the kidney. This is the
osmotic gradient. Water will move passively, by diffusion, from the filtrate into the blood to equalize this
concentration difference. Most of the nutrients, ions, and water is reabsorbed in the PCT with the remaining
sodium and chloride ion and water reabsorption happening in the loop of Henle and DCT.
3. Secretion
This involves the active secretion of waste substances from the blood in the capillary net into the collecting
duct. These wastes include ammonia, urea, uric acid, histamines, excess hydrogen ions, minerals, and
excess drugs (penicillin). This requires active transport and significant amounts of energy from ATP.
Regulation of water (Osmoregulation)
ADH: antidiuretic hormone, produced by the pituitary gland. A diuretic is any substance that increases
urine volume. This hormone increases the permeability of the DCT and collecting duct to water. Since the
urine is hypotonic and the renal medulla is hypertonic water will flow out of the collecting duct into the
capillaries in these regions, decreasing urine volume.
23
Osmoreceptors: are specialized nerve cells that detect changes in water concentration (osmotic pressure).
These receptors are found in the brain (hypothalamus). They will signal the pituitary to produce more
ADH whenever blood water concentration decreases.
Aldosterone: A hormone produced by the adrenal cortex. It increases sodium reabsorption from all parts of
the nephron. This leads to greater water reabsorption from the filtrate/urine into the blood.
Alcohol: Prevents the hypothalamus (brain) stimulation of the pituitary. This decreases ADH production
and results in large volumes of urine. This also causes dehydration.
Regulation of pH (acid – base balance)
Active transport of Hydrogen ions from the blood into the collecting duct (tubular secretion) helps to
regulate the pH of the blood. If excess hydrogen ions are present then the pH is too low and active
transport increases. This decreases hydrogen ions increasing pH back to normal levels.
Disorders of the excretory system
Diabetes mellitus: the inadequate production of or inability to produce insulin. This results in too much
blood sugar (glucose). As the filtrate goes through the nephron it does not lose enough glucose (by active
transport back into the blood). This excess glucose retains/holds water in the urine increasing urine output
and causing dehydration.
Diabetes insipidus: caused by the inability to produce ADH in the pituitary gland. This results in large
volumes of urine and dehydration and possibly death in extreme cases or untreated cases.
Nephritis: an inflamation of the nephron.
Kidney stones: formed by the precipitation of mineral solutes in the urine. This produces tiny stones that
move with the urine and cause extreme pain as they move through the ureter and urethra.
Edema: an accumulation of excess fluid in cells, tissues, or body cavities. This can be produced by an
imbalance of ion, proteins, or damaged tissue.
Renal dialysis: A dialysis machine is used to clean the blood in people whose kidneys are no longer
functional. The blood enters the machine (from an artery in the arm) and passes through a series of dialysis
tubes. The tubes are semipermeable membranes. The tubes a bathed in dialysis solution which is similar to
clean blood plasma (plasma minus urea, uric acid, excess hydrogen ions, and ammonia). Consequently, the
waste materials in the blood diffuse out into the dialysis solution and the cleaned blood is returned to the
body through an tube connected to a vein in the arm.
Peritoneal dialysis: This involves attaching a bag of dialysis solution to a tube that is permanently attached
to the lower abdomen. The dialysis solution is drained into the lower abdominal cavity (the peritoneum)
and left there for a few hours. During this time the waste in the capillaries of the blood lining the
peritoneum diffuse out into the clean dialysis solution. After a few hours the bag is lowered and the
dialysis fluid is allowed to drain out, back into the bag.
24
General Outcome 2: Students will explain how the respiratory system exchanges
energy and matter with the environment.
1. identify the principal structures of the respiratory system i.e.
• nasal passages, pharynx, larynx, epiglottis, trachea, bronchi, bronchioles, alveoli,
diaphragm, rib muscles, pleural membranes
2. explain how gases and heat are exchanged between the human organism and its
environment, i.e., mechanism of breathing, gas exchange, removal of foreign material.
describe the mechanism by which inhalation and exhalation occur
describe the mechanisms involved in the control of breathing
3. explain that the goal of technology is to provide solutions to practical problems
• identify specific pathologies of the respiratory system and the technology used to treat the
conditions
The Respiratory system
Respiration: refers to the cell processes that produce energy. Primarily cellular respiration
Breathing: refers to the exchange of gases between the atmosphere and the lungs
Respiratory System Anatomy
Nasal Sinuses: warm and clean the air
Pharynx: connect sinuses and mouth to trachea
Uvula: small tissue at top of pharynx that prevents food from entering the nose when we swallow
Epiglottus: small tissue that covers the entrance to the trachea (glottis) when we swallow food
Larynx: the voicebox, It sits ontop of the trachea and produces sounds as air moves over the vocal cords
Thoracic cavity: the chest cavity in which the lungs and heart are located.
Trachea: the windpipe. Brings air into and out of the lungs
Bronchi: the two major branches off the trachea that bring air into the right and left lung
Cilia: fine, tiny hairs that trap dust; they clean the air.
Bronchioles: subdivisions of the bronchi that terminate in clusters of air sacs called alveoli
Alveoli: tiny air sacs that have thin membranes and are lined with capillaries. Gases exchange between the
air and the blood occurs across this membrane
Diaphragm: the muscle below the lungs that aids in breathing
Internal intercostal muscles: muscles that pull the ribcage downward during extreme exercise. These are
not used during normal breathing. They cause forced breathing out.
External intercostal muscles: muscles found between the ribs that raise the ribcage, pulling it up and out
causing air to move into the lungs
Pleural membranes: surround the lungs and line the inside of the thoracic cavity. A fluid between these two
membranes helps reduce friction between the lungs and the chest cavity and other organs (heart, and blood
vessels).
The Mechanics of Breathing:
Inhalation
1. intercostal muscles and diaphragm contract
2. thoracic volume increases
3. air pressure inside lungs decreases
4. air from outside (higher pressure) flows into the lungs through nose and mouth
Exhalation
1. intercostal muscles and diaphragm relax
2. thoracic volume decreases
3. air pressure inside lungs increases
4. air inside the lungs is forced out into the atmosphere (now at a lower pressure relative to lungs).
25
Lung volume terminology
Tidal volume: the volume of air inhaled and exhaled under normal breaths
Inspiratory reserve volume: the extra air that can possibly be inhaled after a normal breath in.
Expiratory reserve volume: the extra air that can possibly be exhaled after a normal breath out.
Vital capacity: the sum of the tidal volume, inspiratory reserve, and expiratory reserve.
Reserve volume: extra air left in the lungs after the expiratory reserve volume.
Total lung capacity: the sum of vital capacity and reserve volume
Transport of Gases by the blood
Oxygen
1. dissolved in plasma 1%
2. carried by hemoglobin in red blood cell 99% (forms oxyhemoglobin)
Carbon dioxide
1. dissolved in plasma as CO2 9%
2. carried in plasma as bicarbonate ions 64%
CO2 + H2O react together in a red blood cell where the enzyme carbonic anhydrase speeds up this
reaction forming hydrogen carbonate H2CO3. This compound then breaks down into hydrogen ions H + and
bicarbonate ions HCO3- which diffuse out of the red blood cell into the plasma.
3.attached to hemoglobin in the red blood cell forming carbaminohemoglobin 27%
Regulation of Breathing
Breathing is under both voluntary and involuntary control
Chemoreceptors in the medulla oblongata (part of the brain) are sensitive to the concentration of carbon
dioxide and hydrogen ions in the blood.
When the concentrations of these two chemicals in the blood increases this stimulates the medulla to
stimulate the intercostal and diaphragm muscles causing breathing rate to speed up.
Disorders of the respiratory system
Lung cancer: the uncontrolled growth of cancer cells in the lungs. Most often caused by smoking. The
tumors take up space in the lungs decreasing surface area for gas exchange leading to emphysema and
eventual death.
Bronchitus: an irritation of the cells that line the bronchial tubes causing an increase in mucus production
and tissue swelling. This impairs air flow into and out of the lungs
Asthma: a stimulus causes the bronchiole diameter to decrease making breathing very hard and reducing
oxygen diffusion into the blood and increases blood carbon dioxide.
Emphysema: a buildup of air pressure in the lungs causing a swelling of the alveoli and eventual rupture.
This a long term condition that develops as a result of prolong asthma or smoking. This decrease lung
surface area and oxygen intake in the blood.
26
Unit 5: Energy and Matter Exchange in the Biosphere
General Outcome 1 : Students will explain the constant flow of energy through the
biosphere and ecosystems.
1. explain, in general terms, the one-way flow of energy through the biosphere and how stored
biological energy in the biosphere, as a system, is eventually lost as heat.
1.
The energy the earth/biosphere receives over the long term always balances the energy it gives off.
This satisfies the first law of thermodynamics. The second law of thermodynamics states that when
energy is converted from one form to another the conversion is never 100% efficient. Much of the
energy is lost as heat. This is the heat radiated from the atmosphere, lithosphere, and hydrosphere.
Examples of conversions that release heat are decomposition and muscle contractions
2. First Law of Thermodynamics: The energy that goes into a system must equal the energy that comes
out of a system. Energy in = Energy out.
Second Law of Thermodynamics: Any energy conversion is never 100 % efficient. Some energy is
always lost as heat.
3. Energy flow through the biosphere (distribution of solar energy through the biosphere). The biosphere
consists of the atmosphere, hydrosphere, and lithosphere. Different areas of the biosphere receive
different amounts of energy (latitude, surface features, weather patterns). Different amounts of energy
produce different patterns of life (ecosystems)
4. Overall energy always flow through a system, it drives the system. Energy flows, which in turn
causes matter to cycle and life to exist. It may be temporarily stored, and given off later, it may be
changed from one form to another, but it is never lost. Examples of energy storage processes in the
biosphere are photosynthesis and chemosynthesis.
5. Photosynthesis: occurs in plants, some protozoa, and some bacteria. It is a chemical reaction that
stores energy from sunlight in the chemical bonds of glucose and other sugars. It uses carbon dioxide
and water, occurs in special cell organelles (chloroplasts in plants cells) and produces sugars and
oxygen
6. Chemosynthesis: is a process that occurs in some bacteria that usually live in habitats with no light.
These organisms use the organic chemicals in the environment around them to produce carbohydrates.
The energy to link the molecules together comes from heat in the surrounding environment. Usually
these bacteria are found in the ocean floor around geothermal vents (hot water springs)
7. Energy transfer through the biosphere is by conduction, convection, or radiation, or by energy stored in
compounds in organisms which then pass the energy onto other organisms when they are eaten or
decomposed.
8. Conduction: transfer of energy by direct contact ex. Heat transfer through metal bar
9. Convection: transfer of energy through a fluid ex. Warm air rises, convection currents
10. Radiation: transfer of energy through electromagnetic waves, ex. Light, microwaves, infrared
2. explain how biological energy in the biosphere can be perceived as a balance between both
photosynthetic and chemosynthetic, and cellular respiratory activities
Photosynthesis and chemosynthesis both store energy in larger carbohydrate molecules. Cell respiration
takes the large carbohydrate molecules and slowly releases this energy. The energy is used to do cellular
processes (metabolism) such as building other molecules and is used to keep the cell warm. The waste
products of respiration are reused by photosynthesis or indirectly by chemosynthesis to form the large
carbohydrates again.
Energy flow in photosynthetic environments starts with the sun (visible light) and continues through plants
to animals and finishes with decomposers, forming food chains and webs.
Energy flow in deep sea vents starts with thermal energy from the water (produces by nuclear breakdown
of matter in the Earths crust) to bacteria to protozoa to animals to decomposers.
As light intensity increases the rate of photosynthesis increases and the amount of energy storage by plants
increases (their carbohydrate production increases).
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3. explain the structure of ecosystem trophic levels, using models such as food chains and
webs
1.
2.
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Ecology: the study of ecosystems
Ecosystem: A community and its physical and chemical environment
biotic: the living organisms in an ecosystem
abiotic: the nonliving factors in the ecosystem (the physical and chemical environment
Ecological niche: The role an organism occupies in the ecosystem. There are three basic niches.
Trophic level: the location of an organism in the food chain. Also called its ecological niche.
Producer: Are plants. They take a form of energy and use it to make carbohydrates and other large
compounds out of inorganic compounds (carbon dioxide, water).
Autotrophs: are producers, plants or chemosynthetic bacteria
Heterotrophs: are consumers, usually animals that eat animals or plants
Consumer: Organism that eat producers or other consumers.
Decomposer: convert dead material back into smaller compounds, raw nutrients, to be reused by
producers or other organisms in the environment.
Primary consumer: A consumer that eats producers. A herbivore
Secondary consumer: A consumer that eats primary consumers. A carnivore
Tertiary consumer: A consumer that eats secondary consumers. A carnivore. Usually at the top of a
food chain.
Habitat: The environment a specific organism survives in.
Geographic range: the total area in which an organism lives on the planet.
Herbivore: An animal that eats plants only
Carnivore: An animal that eats animal tissue only.
Omnivore: An animal that eats both plant and animal tissue on a regular basis.
Scavenger: An animal that eats dead animals.
Detritivore: An animal that eats detritus
Saprotroph: An organism that digests its food outside its body then takes it in. Ex. Fungus, molds.
They are fit into the decomposer niche
Detritus: Any organic waste from animals and plants.
food chain: A linear illustration of who eats whom in an ecosystem
Food web: a series of interlocking food chains that illustrates who eats whom in an ecosystem. This
represents the transfer of energy and organic matter through the trophic levels in an ecosystem.
Biological magnification (bioamplification): The buildup of toxic chemicals in organisms as tissues
containing the chemical move through the food chain. The toxic chemicals are absorbed by fatty tissue
and stay in the body of the organism.
4. explain quantitatively the energy and matter exchange in aquatic and terrestrial ecosystems,
using models such as pyramids of energy, biomass and numbers.
Ecological pyramids: another type of illustration of the flow of energy, matter and numbers in an
ecosystem.
Pyramid of numbers: Illustrates the total numbers of each organism in a food chain. The producer numbers
are placed at the bottom while the top carnivore numbers are placed at the top of the pyramid.
Pyramid of biomass : Illustrates the total biomass of the total population of each organism in a food chain.
The producer biomass is placed at the bottom while the top carnivore biomass is placed at the top of
the pyramid.
Pyramid of energy: Illustrates the total energy in the population of the organism in each trophic level in a
food chain. The producer energy is placed at the bottom while the top carnivore energy is placed at the
top of the pyramid.
As energy flows through ecosystems, stored in the chemical bonds in the organic compounds that compose
the cells and cell compounds of the organism, some energy is always lost as heat, used by the organism for
body functions, or released in the waste produced as the organism lives its life Therefore not all the energy
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an organism receives will be passed on to the next tropic level. The standard number used is 10%. Ten
percent of the energy from one tropic level is used to support the next tropic level. This places a limit on
the number of tropic levels in any given food chain or web. It also places a limit on the numbers of
organism, and their biomass, at each tropic level. This can be illustrated in food chains or food webs, or in
ecological pyramids. This also explains the shape of ecological pyramids. Their bases are very large,
meaning a lot of energy, biomass, and numbers exist at the producer level, but as you go up the pyramid, to
higher levels in the food chain, the available energy decreases with a corresponding decrease in biomass
and numbers.
General Outcome 2: Students will explain the cycling of matter through the
biosphere.
1. explain and summarize the biogeochemical cycling of carbon, oxygen, nitrogen and
phosphorus, and relate this to general reuse of all matter in the biosphere
2. explain water’s primary role in the biogeochemical cycles, using its chemical and physical
properties, i.e., universal solvent, hydrogen bonding.
3. explain that science and technology have both intended and unintended consequences for
humans and the environment
4. discuss the influence of human activities on the biogeochemical cycling of phosphorus,
sulphur, iron and nitrogen
Biogeochemical cycles
1.
2.
3.
Biogeochemical cycles involve the cycling of matter. These include the carbon, water, nitrogen, and
phosphorous cycles. The substances are all important in various life processes
Energy from the sun is the principle driving force within all these cycles
But just as energy is important to drive these cycles (a top down approach) decomposers are equally
important to keep matter available to be recycled (a bottom up approach). Hence if either the energy
source is deprived or the decomposers (bacteria, worms, and insects) are eliminated the biosphere
would lose its steady state equilibrium, it would lose its balance, it could not continue. An example of
this was witnessed in Biosphere II project.
The Water Cycle
Uses of water:
1. water makes up 70-99% the body mass of all living things
2. it is the major compound in living cells
3. needed for digestion, transport, cooling, location where reactions occur
Properties of water that make it essential for live:
1. Universal solvent: Water dissolves more substances on earth than any other liquid. It dissolves
both gases and solids allowing water to carry gases and nutrients throughout multicelled
organisms, making up the principle component of all circulatory systems.
2. high heat capacity: Water has high heat capacity. This means it hold heat very well. It takes a
long time to heat up, but also takes a long time to cool down. Therefore water acts as an insulator
from both cold and hot extremes.
3. Cohesive: water molecules stick together very well. This is due to the intermolecular bonding
forces, hydrogen bonding, dipole-dipole, and London dispersion. This allows some organisms to
“float” on top of water. This also allows water to be pulled in a continuous stream up xylem in
plants from roots to leaves, the cohesion tension theory of water transport in plants.
4. Adhesive: water molecules also stick to other surfaces (due to hydrogen bonding). This allows
water to act as a lubricant, protecting joint surfaces on all moveable joints in vertebrates and
invertebrates. It also allows water to reduce friction between organs that can rub together (heart
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5.
and lungs). It also allows water to stick to the xylem cells, holding it against gravity, allowing
water to be pulled up from roots to leaves against the force of gravity.
Density: an anomalous property, when water freezes its density decreases therefore ice floats
Steps of the water cycle
1.
2.
3.
4.
5.
6.
7.
8.
Evaporation: solar energy converting liquid water to water vapor
Condensation: as water rises in the atmosphere it cools, converting from water vapor to liquid
water or to snow or ice crystals in the atmosphere, forming clouds.
Precipitation: Water in clouds falling to the ground as rain, snow, sleet, hail.
Transpiration: water evaporating from the surface of leaves, through stomata, into the atmosphere
Runoff: excess water that flows off the surface of the land forming rivers and streams, flowing to
lakes or ponds, and eventually to the oceans.
Percolation: The movement of water through the topsoil, through the ground, into the
groundwater.
ground water: water stored in porous rock below the soil. It can form large bodies of water in
porous rock called aquifers.
water table: The top surface of the ground water aquifer.
Unintended consequences of human interference = Acid Rain
The water cycle and acid rain
1.Acid rain is rainwater below the pH of 5.6
2. combustion of fossil fuels produces nitrogen and sulfur oxides
3. These compounds mix with water in the air forming nitric and sulfuric acid.
4. When these compounds fall to the ground they damage both living and nonliving things
5. acid rain leaches toxic metals from the soil which can be absorbed by plants and then the plants ingested
by animals. These metals bioamplify in the food chain having serious effects on top carnivores.
6. acid rain damages living tissues in plants
7. it also damages steel, concrete, and marble statues and building exteriors.
8.it is fixed by scrubbers, adding lime to lakes, more efficient engines, reduced use of fossil fuels
The carbon cycle
Carbon is one of the essential elements in all living organisms. Because of its ability to form 4 chemical
bonds with other elements it can make an almost infinite array of different compounds. Carbohydrates,
fats, proteins, and vitamins are all composed of carbon atoms.
Steps in the carbon cycle
1. photosynthesis: carbon dioxide + water in chloroplasts with chlorophyll and sunlight produces
oxygen and glucose
2. cellular respiration: oxygen + glucose in the mitochondria produces carbon dioxide and water,
heat and ATP (cellular energy)
3. fossilization: a long geological process where dead plant and animal material is converted into
hydrocarbon compounds (crude oil)
4. combustion: the addition of oxygen to hydrocarbons to produce carbon dioxide and water and heat
5. volcanic eruptions: release large amounts of carbon dioxide into the atmosphere
6. diffusion: the oceans cover 75% of the planet. Carbon dioxide gas in the atmosphere can diffuse
into the oceans and well as diffuse out of the oceans. The overall extent of the effect of oceans on
carbon dioxide in the atmosphere is not known. The oceans could act as a large‘sink’ holding
large amounts of carbon dioxide gas, which may be released at a later period.
Unintended consequences of human interference = enhanced greenhouse effect
Precautionary principle: if the effects of human induced change would be very large, those responsible
must prove that it will not do harm before proceeding.
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The carbon cycle and the greenhouse effect
1. Carbon dioxide is produced during fossil fuel combustion, forest fires, decomposition, respiration,
volcanoes, and deforestation reduces carbon dioxide consumption by plants (less plants).
2. Carbon dioxide allows light to pass through but traps reflected heat. This is the greenhouse effect
3. The greenhouse effect keeps the earth warm and allows life to exist. But too much carbon dioxide
can increase global temp too fast. Global warming may also be influenced by solar cycles
4. The role of the oceans in storage and release of carbon dioxide is not known. Since the ocean
covers 75% of the surface of the earth and has tremendous volume it could have a significant
effect on carbon storage (increasing global temp would increase water/ocean temp and water holds
less gas at warmer temp)
5. This can cause melting of glaciers and icecaps, increasing the level of the ocean, flooding coastal
cities, increased storms, hurricanes, tornadoes, and shifts in global weather and climate
The nitrogen cycle
Nitrogen is an important element in proteins. Proteins are essential in all living cells and viruses. Proteins
are used to make important compounds for living organisms, antibodies, hormones, enzymes. The major
storage form of nitrogen is nitrogen gas in the atmosphere. Nitrates are usable form plants get there
nitrogen in, plants can not use nitrogen gas in the atmosphere.
Steps in the nitrogen cycle
1. nitrogen fixation: performed by bacteria (nitrogen fixing bacteria) in the soil, they convert
atmospheric nitrogen gas into nitrates which are usuable to plants. The most common bacteria that
do this (Rhizobium) and found in root nodules of the legume (vegetable) family of plants.
2. denitrification: the reverse of nitrogen fixation. Bacteria in the soil convert nitrates to nitrogen
gas
3. ammonification: the breakdown of organism waste products (proteins) into ammonia by bacteria
4. decomposition: the breakdown of waste products into other compounds by bacteria and protozoa
5. assimilation/protein synthesis: the uptake of nutrients from the soil and encorporation of those
into the organisms cells
6. lightning: converts atmospheric nitrogen into nitrates
7. eutrophication: the filling in of a lake by organic matter and silt. This usually results in an increase
in plant and animal population growth with results in increased oxygen consumption from the
water and may lead to death of most organisms in the lake due to loss of oxygen.
Phosphorous cycle
Phosphorous is used in cell membranes and for energy storage in cells (ATP)
Steps in the phosphorous cycle.
1. weathering and erosion: these processes remove phosphates from rocks and soil, releasing them into
the atmosphere, streams and rivers.
2. Runoff: excess water from rainfall leaches phosphates from the soil or rocks carrying the phosphates to
ponds, lakes, and oceans.
3.
4.
5.
Decomposition: the breakdown of waste products or dead bodies into other compounds by bacteria and
protozoa
Assimilation: the uptake of nutrients from the soil and encorporation of those into the organisms cells
Eutrophication: the filling in of a lake by organic matter and silt. This usually results in increase animal
population growth with results in increased oxygen consumption from the water and may lead to death
of all organisms in the lake due to loss of oxygen. Excess phosphates in runoff from fields or in the
water from sewage and treated water from cities and towns enhance eutrophication.
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5. discuss the use of water by society, the impact such use has on water quality and
quantity in ecosystems, and the need for water purification and conservation
Other than the air we breath (oxygen gas is all we use from the air) water is the next most important,
essential substance all living things, and human societies, need to survive. Urban expansion (called urban
sprall) has filled in many wetland areas, altered streams, and added wastewater and urban pollution to
rivers and streams. Human consumption and cleaning, industrial mining, oil and gas, and agricultural use
(irrigation) consumes tremendous amounts of water. All these add to the “drain” on freshwater supplies in
Alberta and Canada. This often results in water restrictions at different times of the year when water
shortages develop, when the production of clean water by water treatment plants falls below the
consumption by humans. In rural settings these restrictions can also happen if not enough rainfall occurs
and the water table falls and wells run dry. Also, mining and oil and gas use and exploration, and
wastewater production by numerous industries can damage fish habitat and have tremendous effects on
spawning.
With increased human demand for water and increased desire to protect freshwater and saltwater
ecosystems, there is an increased need for faster water purification and water conservation.
6. analyze the relationship between heavy metals released into the environment and
matter exchange in natural food chains/webs, and the impact of this relationship on the
quality of life.
Heavy Metals in the Food Chain/Web
Mercury
Sources: mining
Effects: behavior disorders
Lead
Sources: old paint
Effects: damages nerve cells, learning disabilities, anemia,
General Outcome 3: Students will explain the balance of energy and matter
exchange in the biosphere, as an open system, and how this maintains equilibrium.
1. explain the interrelationship of energy, matter and ecosystem productivity (biomass
production
Primary Productivity of Ecosystems
Increased solar energy leads to increased photosynthesis measured as increased primary productivity
measured as increased biomass of the ecosystem.
Primary productivity can be determined by measuring the growth of plants in an area. The total plant
material in a defined area can be removed, dried, and weighed and then compared between different
ecosystems to determine which is more productive, or which receives more energy. (Quadrat sampling)
Rainforest vs desert
Rainforest has tremendous productivity. It receives sunlight 12 hours per day for 365 days of the year.
Combined with large amounts of precipitation and fast decomposition, plants grow very well here. In
contrast deserts are typified by low productivity due to a lack of precipitation.
Intertidal zone vs deep sea
Intertidal zone has high productivity compared to deep sea primarily because of a lack of sunlight in the
deep sea and a lack of producers.
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2. explain how the equilibrium between gas exchanges in photosynthesis and cellular
respiration influences atmospheric composition
The balance that exists between photosynthesis and cell respiration has a significant effect on the
concentration of oxygen and carbon dioxide in the atmosphere. Photosynthesis uses carbon dioxide in the
atmosphere and produces oxygen while cell respiration produces carbon dioxide and uses oxygen. If not
enough photosynthesis happens (due to deforestation or altering the ph of the oceans) carbon dioxide levels
can increase.
3. describe the geological evidence (stromatolites) and scientific explanations for change in
atmospheric composition, with respect to O2 and CO2, from anoxic conditions to the present
and the significance to current biosphere equilibrium.
Evidence for Climate Change
Stromatolites: are fossils found in sedimentary rock. These tell us that the current temperate climate
regions of the world were once tropical because we find fossils of tropical plants and animals in these
regions.
Current trends indicate carbon dioxide emissions are increasing, increasing atmospheric carbon dioxide,
which enhances the greenhouse effect. This could lead to a warming trend in the earths climate with
corresponding changes in global ecosystems.
General Outcome 4: Students will explain that the biosphere is composed of
ecosystems, each with distinctive biotic and abiotic characteristics.
1. define and explain the interrelationship among species, population, community and
ecosystem
Species: members of a population that can reproduce together to produce fertile offspring
Population: members of the same species that are in a defined area at a specific time
Community: populations of different organisms that exist in the same area
Ecosystem: the interaction of the biotic and abiotic components in a characteristic environment
2. explain how a terrestrial and an aquatic ecosystem supports a diversity of organisms through
a variety of habitats and niches
The biosphere contains many types of ecosystems. The can be divided into terrestrial (land) and aquatic
(water) ecosystems.
Terrestrial Ecosystem niches: Vertical stratification in forests
Canopy: The uppermost layer of the forest where most of the leaves on the trees are found
Sub-canopy:The region below the canopy composed mostly of tree trunks with no leaves
Forest floor: The top surface of the ground of the forest
Soil: The dirt below the forest floor
3. identify biotic and abiotic characteristics and explain their influence in an aquatic and a
terrestrial ecosystem in a local region
Aquatic ecosystems (marine)
Marine ecosystems can be further divided into freshwater (lakes, rivers, ponds) and saltwater (oceans/seas)
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A. Freshwater ecosystems.
Lakes and ponds:
a) Littoral zone: the shallow water zone around the perimeter of a lake or pond. Contains submergent
vegetation.
b) Limnetic zone: the open water zone that light penetrates through. May contain vegetation floating on
top but no vegetation rooted from the bottom growing up through it.
c) Profundal zone: the deep water zone where no light can reach. The bottom region of deep lakes.
d) Benthic zone: the bottom layer of the entire pond or lake. Consists of mud and plant and animal waste.
This is where decomposition occurs.
e) Plankton: any small free floating organism suspended in the water
f) Zooplankton: The plankton that are animals, are herbivorous or carnivorous
g) Phytoplankton: The plankton that are plants, they undergo photosynthesis and are the major producers
in almost every aquatic ecosystem.
B. Saltwater ecosystems.
Oceans and seas
1. Intertidal zone: the region where ocean meets the land. Where the tides intermitently expose and then
cover the land.
2. neritic zone: the region of water above the continental shelf where most marine organisms live (coral
reefs are found here)
3. Continental shelf: the gradual descending of the continent below the surface of the ocean.
4. Oceanic zone: the region of open water beyond the neritic zone, past the continental shelf.
5. Euphotic zone: the upper region of the oceanic zone through which light can penetrate (max depth
100m.)
6. Aphotic zone: the region below the euphotic zone where light does not penetrate.
7. Abyssal zone: the lowermost depth of the ocean including trenches. It also has no light
8. zooplankton: The plankton that are animals, are herbivorous or carnivorous
9. Phytoplankton: The plankton that are plants, they undergo photosynthesis and are the major producer s
in almost every aquatic ecosystem.
4. explain how limiting factors influence organism distribution and range
Limiting factors (how they influence range and distribution)
Examples: water availability, temperature, food availability, disease, predators
Increases in these factors restrict the range and distribution of populations. Organisms only exist within
the range of tolerance to their resources that support them.
5. explain the fundamental principles of taxonomy, i.e., domains, kingdoms and binomial
nomenclature.
Classification and Taxonomy
Why classify organisms
 Species identification—it is easier to find out which species an organism belongs with if
organisms are already classified rather than in a disorganized catalogue.
 Predictive value—if several members of a group have a characteristic, another species in this
group will probably also have this characteristic.
 Evolutionary links—species that are in the same group probably share characteristics because they
have evolved from a common ancestor, so the classification of groups can be used to predict how
they evolved.
Taxonomy –is the process of classifying or organizing organisms into groups based on shared
characteristics. It uses a system of rules to group or classify organisms.
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Taxonomy was highly refined by Carl Linnaeus. He developed the system of binomial nomenclature. This
means that every organism can be identified using two names.
The rules for binomial nomenclature are as follows:
 The first name is the genus name
 The genus name is given an upper-case first letter
 The second name is the species name
 The species name is given a lower case first letter
 Italics are used when the name is printed
 The name is underlined if it is handwritten
Modern taxonomy divides all organisms on the planet in to five kingdoms, each with 8 other subdivisions,
the last two always being the genus and species. The 7 levels of classification are: kingdom, phylum, class,
order, family, genus, and species. Species are defined as a group of organisms that can reproduce together
to produce fertile offspring.
Examples
Taxon
Kingdom
Phylum
Class
Order
Family
Genus
species
Humans
Animalia
Chordata
Mammalia
Primate
Hominidae
Homo
sapiens
Great white shark
Dichotomous Keys
A classification tool used by taxonomists to identify the name/taxon of an unkown organism. They consist
of a series of numbered statements. Each series consists of a pair of alternative characteristics. Some
alternatives lead to the next set of statements and characteristics while other alternatives state the name of
the organism.
General Outcome 5: Students will explain the mechanisms involved in the change of
populations over time.
1. Describe modern evolutionary theories, i.e., punctuated equilibrium versus gradualism.
Evolutionary Theory: A Historical Development
1.
Greeks: Aristotle, Plato (400-300B.C.)
There are ideal forms, meaning organisms can change
2.
Renaissance: Davinci, Galileo, Newton (1400-1600)
The earth is not the centre of the universe
3.
George Cuvier: Started the study of fossils (paleontology)
Reconstructed ancient animals from fossils
These animals were not alive today but must
Have lived in the past.
4.
Lyell Hutton: Used radiometric techniques to find the age of the Earth. Found the earth is 4-5 billion
years old
5.
Jean Lamark: (1800’s) Inheritance of Aquired Characteristics.
Proposed one of the first mechanism for how evolution occurs.
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6.
Darwin and Wallace: (1800’s) Developed the theory of Natural Selection.
7.
Modern theories:
Neodarwinism
Punctuated Equilibrium vs gradualism
Origin of prokaryotic and eukaryotic cells
Endosymbiotic theory
Panspermia
Special creation/creation science/intelligent design theory
Scientific theories vs nonscientific theories
2.explain that variability in a species results from heritable mutations and that some mutations
may have selective advantage(s)
The importance of variation in populations
Variation allows for the survival of a population should the environment change in a way harmful to most
of the members. Variations breeds stability of the population. If a population has no variation and the
environment changes in such a way as to be harmful to the population the change will cause increased
mortality causing decline in population numbers and possible extinction of the population and species. If
variations exist, one such variation may prove to be an adaptation to this change in environment and those
members with the variation /adaptation will survive/live longer reproduce more and pass on their
characteristics to a greater percentage than those members that do not have the adaptation (they have better
reproductive fitness)
There are four types:
Inherited variation- those characteristics passed on through the genes carried on chromosomes in the sperm
or egg cell. Ex. Blood types (A, B, AB, O, eye color, normal and abnormal lactose enzyme)
Acquired variation-those characteristics received from the environment and are not passed on to future
offspring; do not affect genes in chromosomes of the sperm or egg cells. Ex. Cuts, scars, tan lines, dying
your hair, amputation of a finger.
Continuous variation- traits that show graduation of small differences. Ex. Height in humans
Discontinuous variation – traits that do not show graduation of small differences. Ex. Comb shape in
chickens. Rose, single, pea, and walnut, there are not intermediates.
Mutations
Mutations are changes in the genetic information of a cell. Only mutations in the chromosomes of sperm or
egg cells are passed on to future generations. Mutations are caused by chemicals in the environment, heat,
radiation, and some viruses.
Adaptations and Adaptive significance
Characteristics that make an organism better suited to live and reproduce in their environment
Ex. Thick fur in polar bears, excellent night vision in owls.
Adaptive significance is the importance of an adaptation to an organism in its environment. What purpose
does this characteristic serve the organism.
3. discuss the significance of sexual reproduction to individual variation in populations and to
the process of evolution
Sexual reproduction allows for the mixture of characteristics from two parents. Both parents contribute
half of their genetic information to each offspring. The characteristics the offspring express are determined
by the combinations of genes they inherit from their parents. This produces variation in all offspring.
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4. compare Lamarckian and Darwinian explanations of evolutionary change
Inheritance of Acquired Characteristics
Lamark’s theory, also called the law of use and disuse. According to this theory an organism can change
its body characteristics during its lifetime. That by using a certain part of its body this part would slowly
change to be better adapted to the environment, through continual use. Conversely, that if a body part were
not used over the lifetime of the organism it would slowly lose its function, slowly disappear. Also, that
the acquired (modified) characteristic would then be passed on in its modified form to its offspring.
Weaknesses: The environment does not caused directional mutations: the environment does not cause
mutations in genes of characteristics that are used more than genes that are not used for that specific
behavior or adaptation.
Darwin and Wallace’s theory of natural selection
Darwin and Wallace developed the same explanation simultaneously and independently. It has five
specific points:
1. overproduction: all populations have the capacity to produce more offspring than what the
environment can sustain.
2. Variation: within natural populations differences always exist between individuals.
3. Struggle for existence: competition exists between and within species for food, water, shelter, mates,
space.
4. Survival of the fittest (natural selection) Those members that have the best adaptations to the
environment will live longer and reproduce more (have greater reproductive fitness), passing on their
characteristics in the population more than other members that do not have those adaptations. ( this
does not exclude cooperation, the adaptation could be anything that increases the chance of survival
and reproduction)
5. Origin of new species: Speciation- the process of forming new species. This occurs through
geographic isolation. Groups of individuals of the same species become separated from each other,
and therefore cannot reproduce. Over time small changes occur in each population (microevolution)
until eventually the groups are so different they cannot reproduce to produce fertile offspring. At this
point a new species has been created (macroevolution)
5. summarize and describe lines of evidence to support the evolution of modern species from
ancestral forms
Evidence for Evolution
There are two major divisions of evidence for evolution: Direct and indirect observation
Direct observation includes Fossils and microevolution while indirect involves embryology, comparative anatomy,
physiological, and biochemical evidence.
A. Direct Observation
Fossils- The remains (bones, bodies, body material) impressions and traces of organisms from past
geological ages. They provide a record (pictures) of past life. Many fossils represent species that have
become extinct. They indicate that the earth is very old and that life forms change over time. Fossils
form when 1) the organism is buried quickly; 2) it decays leaving spaces; 3) the spaces are filled with
silt and minerals over the years. This results in bones or materials that have become rock. If the
organism decays it may leave behind a fossilized imprint in the rock that forms.
The age of fossil evidence is determined using a technique called radiometric dating (Carbon dating).
This is a method of determining the age of rocks using radioactive decay of elements in the rock sample. Isotopes of
elements are often unstable and will spontaneously change into other isotopes of the same element or different
elements. The time it takes to decay from one substance to another is different for each different element. The Half
Life of an isotope is the time it takes for one half of the mass to decay into the new substance. Half lives vary from
seconds to millions of years.
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Examples: potassium 40 into argon 40 half life is 1.3billion years
Carbon 14 into nitrogen 14 half life 5730 years
The isotopes are chemically the same as the normal element but exist in much smaller amounts in nature. When an
organism dies it stops taking in nutrients and gases, consequently its uptake of these isotopes also stops. When a
fossil is found a measurement is made as to the amounts of isotopes are present in the sample. The approximate age
can be determined based on a simple decay curve for that isotope. Given this techniques scientists have determined
the age of the earth to be 4-5 billion years.
Also, the rocks tell of different periods in geologic history that are characterized by different life forms and
dominated by different life forms. This is called the geologic time scale
Microevolution- the accumulation of small changes in the characteristics of a population. Through natural
selection this fits organisms to their environment. It does not directly produce new species. Speciation
occurs through macroevolution. Peppered Moths population color changes and antibiotic resistance in
bacteria are an example of microevolutionary change. Both these changes happened in response to
environmental changes.
B. Indirect Observation
Embryology- the study of the embryo and fetal development. The more similar the embryo development
the more recent the evolutionary ancestor.
Comparative Anatomy- organisms with similar structures implies a common ancestor
a. analagous structures- are similar in function and appearance but not in origin. The wing of an
insect and the wing of a bird. This also indicates that similar adaptations develop (evolve) under
similar environmental pressures. This is called convergent evolution, the development of similar
forms from unrelated species due to adaptation to similar environment.(ex. ocean mammals and
fish have the same body shape and adaptations but both evolved from different ancestors)
b. homologous structures- have similar origin but different uses in different species. The front
flipper of a dolphin and the forelimb of a dog. This indicates they share common ancestory. Their
body parts are the same but over time have been modified (adapted through mutations, natural
selection, and environmental pressures) to be used in different environments for similar or
different purposes. This is called divergent evolution.
Physiological- The study of the function of the parts of an organism. Ex. human, cow, and pig insulin can
be interchanged. Wastes from birds and reptiles are the same.
Biochemical- All organisms have DNA. This is the molecule that makes up the chromosomes and carries
the instructions to make all parts of the organism. The DNA of every organism is made of the same
parts. The sequence in the DNA makes different organisms different. Similar organisms have more
similar DNA, this indicates they have a more common ancestor than compared with organisms that
have more dissimilar DNA. The more different the DNA of two organisms the further in the past was
their common ancestor (evolutionary clock). Changes in DNA (mutations) are caused by temperature,
radiation, chemicals, and by spontaneous means. An extension on this concept is the evolutionary
clock theory which states that the greater the difference in the amino acid sequence of the same protein
in different organisms the further back in time was their common ancestor.
Biogeographical distributions- Similar species are found in similar habitats in different parts of the world.
Natural selection molds an organism to its environment, since land masses were once together these
organisms at one time were part of one population that became isolated as the continents split apart.
Consequently these similar species have unique differences. Example 1: big flightless birds—rhea, emu,
ostrich, 2: placental marsupial, and monotreme mammals. All mammals have hair, internal fertilization,
warm blooded, and breast feed. The placental mammals the fetus develops in the uterus, are found all over
the world except Australia. The marsupials the fetus develops in a external pouch, they are found mostly in
Australia, there is one north American marsupial, the opossum. The monotremes lay eggs and incubate.
They are only found in Australia, New Guinea, and Tazmania.
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5. explain speciation and the conditions required for this process
Types of speciation
Allopatric speciation (in different geographic areas)—caused by geographic isolation. Members of a
population isolate themselves from the parent population and over long periods of time through the
accumulation of mutations that survive because of living in a different environment (acquiring new
adaptations) they develop different features and eventually will not reproduce with the parent population.
This takes thousands of years and the right environmental conditions
Sympatric speciation(in the same geographic area)—caused by mutations that cause changes in location
populations that prevent them from reproducing. When two or more populations of the same species that
live in the same area but develop mutations that prevent them from reproducing together. This is also
called adaptive radiation
The pace of evolution: Two theories explain how fast speciation occurs.
1.
2.
Gradualism, slow progressive change from one species into another (s).
Punctuated equilibrium, fast changes (geologically speaking) followed by periods of stability.
The fossil record shows evidence for both theories.
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