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BIOLOGY 20 STUDY GUIDE 2013-2014 Holy Trinity Academy 1 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, 2 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 3 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). 4 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 5 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 6 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 7 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 8 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 9 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. 10 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 8 4 8 12 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. 11 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 12 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. 13 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 14 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). 27 3. explain the structure of ecosystem trophic levels, using models such as food chains and webs 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 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 28 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 29 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. 30 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. 31 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. 32 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) 33 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. 34 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. 35 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. 36 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. 37 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. 38 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. 39