Download Digestion and Enzymes - SHS-Foundations-Biology-2014

Nutrition, Digestion and Enzymes
You are what you eat!
Objectives
Topic 30.2: Nutrition
1. Explain how food provides energy.
2. Identify the essential nutrients your body.
3. Explain how to plan a balanced diet.
Vocabulary:
Calorie
Carbohydrate Fat
Protein
Vitamin
Mineral
Elements of Life
Organic Compounds
• Carbohydrates (sugars) : Carbon, Oxygen,
Hydrogen
• Lipids (fats): Carbon, Oxygen, Hydrogen, and
Phosphorus
• Proteins: Carbon, Oxygen, Hydrogen,
Nitrogen, and Sulfur
• Nucleic Acids (DNA, RNA): Carbon, Oxygen,
Hydrogen, Nitrogen, Phosphorus (not really
food)
Nutrition
• Nutrient – substance that supplies energy and raw
material for growth, maintenance, and repair.
- water for all of life’s activities
-carbohydrates for energy
- fats (lipids) for cell membranes, hormones
- proteins for enzymes, structures, transport
- vitamins for working with enzymes to regulate body
processes
- minerals such as calcium/bones, iron/hemoglobin,
sodium & potassium/nerve function
Calorie
• When food is burned, energy is converted to
heat.
• Calorie= amt. of heat to raise the
temperature of 1 g of H2O 1 degree Celsius
• c = 1 calorie C= 1,000 calories = kilocalorie
• 1 gram of Carbohydrates = 4 Calories
• 1 gram of Protein = 4 Calories
• 1 gram of Fat (lipids) = 9 Calories
Water
• Dehydration – abnormal depletion of body
fluids
• The major component of blood
• Necessary for
– Electrolyte and pH balance
– Transporting cells and O2
• Recommended amount – 8 glasses/day (64
ounces)
• 50-60% of body is water
Protein
• Second most abundant substance in humans
• Key to every cell, antibodies, enzymes, and
hormones
• Transport oxygen and nutrients
• Role in developing/repairing bone, muscle, skin
• Vital for human life
– May need additional protein if fighting off infection,
recovering from surgery or blood loss, recovering from
burns
• Amino acids
Proteins
– Building blocks of protein
• 20 essential amino acids must be obtained from food
• 11 non-essential amino acids produced by the body
– Link together to form
• Complete protein – supplies all essential amino acids
• Incomplete protein – may lack some amino acids, but
these can be easily obtained from different sources
• Few Americans suffer from protein deficiencies
Carbohydrates
• Best fuel – provide energy quickly and
efficiently
• Two types
– Simple sugars
• Glucose (monosaccharide) – most common form
• Fructose (monosaccharide) – found in fruits and berries
• Sucrose (disaccharide) – sources include granulated
sugar, milk and milk products
– Complex carbohydrates (polysaccharides)
• Starches – from flour, pasta, potatoes
– Stored in the body as glycogen
• Fiber
Fiber
• “Bulk” or “roughage”
• Indigestible portion of plants
• Insoluble
– Found in bran, whole-grain breads, most fruits and
vegetables
– Found to reduce risk for several forms of cancer
• Soluble
– Oat bran, dried beans, some fruits and vegetables
– Helps lower blood cholesterol levels
– Helps reduce risk for cardiovascular disease
Fiber
• Offers many health protections
–
–
–
–
–
–
–
Colon and rectal cancer
Breast cancer
Constipation
Diverticulosis
Heart Disease
Diabetes
Obesity
• Most American eat far less than recommended
– Recommended is 20-30 grams and average is 12 grams
Fats
• Also called lipids
• Misunderstood but vital group of basic nutrients
–
–
–
–
–
–
Maintain healthy skin
Insulate body organs
Maintain body temperature
Promote healthy cell function
Carry fat-soluble vitamins A, D, E, and K
Are a concentrated form of energy
• You should have ABOUT:
• 50 grams of protein (20-25% of total Calories)
• 50 grams of fat (20-25%)
• 250 grams of carbohydrates (50-65%)
Each day.
But it depends on your total Calorie intake.
Fast Food Nutrition
• http://www.fastfoodnutrition.org/fast-foodrestaurants.php
• What’s your favorite meal?
• Is it nutritious?
Objectives
Topic 30.3: Digestion
4. Describe the organs of the digestive system.
5. Explain what happens during digestion.
6. Describe how nutrients are absorbed into the
bloodstream and wastes are eliminated from the
body.
Vocabulary:
Amylase Esophagus
Peristalsis
Stomach
Pepsin
Small intestine
Villi
Large intestine (colon)
Digestion
• To break down food into simple molecules
that can be used by body.
• Two types of digestion:
- Physical (mechanical) digestion: Breaking
down of food into smaller pieces.
- Chemical digestion: Breaking down of
macromolecules, polymers into smaller
molecules.
Major Organs
MOUTH (ORAL CAVITY)
Accessory Organs
SALIVARY GLANDS
PHARYNX
ESOPHAGUS
STOMACH
LIVER
GALLBLADDER
PANCREAS
SMALL INTESTINE
LARGE INTESTINE
(COLON)
RECTUM
ANUS
Fig. 37-6, p.620
Digestion-Anatomy
Identify
Digestion
• Mouth
- Teeth tear apart food
(physical digestion)
- Saliva has an enzyme
amylase to break down
starches to complex
sugars. (chemical
digestion)
Digestion
• Esophagus moves food
from mouth to stomach.
• Smooth muscles
contract to swallow food.
• Contractions known as
peristalsis.
Digestion
• Stomach continues
mechanical and chemical
digestion.
• Mechanical – Stomach
muscles contract; mix &
churn food; produce chyme.
• Chemical – HCl and pepsin
(enzyme) work together to
break down proteins into
polypeptides.
Digestion
Accessory Digestive
Structures
• Pancreas- produces
hormones to regulate
blood sugar; produces
enzymes to breakdown
carbohydrates, lipids,
proteins. (chemical)
• Liver produces bile
which breaks down lipids
(fats) to smaller
molecules.
• Gallbladder stores bile.
Digestion
• Small Intestine – 2 functions: complete
chemical digestion and absorption of food
molecules.
• Has 3 parts: duodenum, jejunum, ileum
• Chemical digestion: All molecules broken
down to smallest component glucose, amino
acids, fatty acids, glycerol
Digestion
Absorption of glucose and amino acids occurs at the villi
(finger like projections). Absorbed by blood.
Absorption of fats occurs at the villi; absorbed into lymph
system.
intestinal
mucosa
Fig. 37-10a, p.624
epithelium
villi (fingerlike
projections of
mucosa covered
by epithelium
blood
capillaries
lymph
vessel
connective
tissue
vesicle
artery
vein
lymph vessel
b villi on a mucosal fold
c one villus
Fig. 37-10b, p.624
Fig. 37-11, p.625
Complete
Mechanical Digestion
Mouth
Esophagus
Stomach
Small Intestine
Chemical Digestion
Digestion
• Large intestine functions: Remove water from
undigested material; make vitamin K; expel
waste from body.
Objectives
Topic 2.3: Carbon
7. Describe the unique qualities of carbon.
8. Relate the terms monomer and polymer.
9. Describe the structures and functions of each
of the four groups of macromolecules.
Vocabulary:
Carbon
Lipid
Protein
Nucleic Acid
Monomer
Polymer Carbohydrate
Organic Molecules
• Are made of carbon.
• Can be very small like CO2 to very large like a
protein.
• Living organisms are made of and use organic
molecules.
Carbon
• Is tetravalent; can form 4 bonds.
• Bonds with many types of elements:
H,N,O,P,S
• Can form many types of structures.
Macromolecules
• Macromolecule – Giant molecule made from
smaller molecules.
• Polymer- Large molecule consisting of similar
or identical molecules linked together.
• Monomer – Subunit of polymer.
• Polymerization - Process of polymer creation
Polymerization
Figure 5.2 The synthesis and breakdown of polymers
Organic Molecules
• Carbohydrates, proteins, and nucleic acids are
polymers (and macromolecules).
• Lipids are macromolecules (but not polymers)
• All are biomolecules.
Carbohydrates
• Made of C, H, O in 1:2:1 ratio;
(CH2O)
• Used for energy by all
organisms, plants & some
animals use them for
structures.
• Monosaccharides- single
sugar (monomer)
• Glucose is a monosaccharide
used for energy.
Carbohydrates
• Disaccharides - Two sugars
• Table sugar sucrose is a disaccharide
composed of two monosaccharides glucose
and fructose (fruit sugar).
Carbohydrates
• Polysaccharides are
polymers made of many
monosaccharides.
• Examples:
- Plant starch – used to
store energy
- Glycogen (animal starch)
– used to strore energy.
- Cellulose – used by
plants for structure.
Cellulose
Lipids
• Made from C, H mostly.
• Used to store energy, for cell membranes,
water proof coverings, some hormones.
• Three types of lipids
- Triglycerides
- Phospholipids
- Cholesterol
Triglycerides
• Made of 2
components
- glycerol
- fatty acid chains
(3)
• Used to store
energy (2x energy
in a
polysaccharide)
Saturated vs. Unsaturated
Saturated Lipid•Single bonds between Cs in
carbon skeleton.
•Each C single bonded to H. (i.e.
saturated with H)
•Chain straight / pack tightly
/solids at RT.
Unsaturated Lipid –
•Some Cs double bonded
• Makes kink in chain
• Chains can’t pack as tightly/
oils at RT.
Figure 5.11 Examples of saturated and unsaturated fats and fatty acids
Saturated vs. Unsaturated
• Saturated fats
- Animal fats
- Raise LDL or bad cholesterol levels.
• Unsaturated fats
-Vegetable fats
- either help to raise HDL or good
cholesterol levels or decrease LDL levels.
Cholesterol
Steroids- lipids with 4
fused carbon rings.
Cholesterol is a steroid.
Function- component of
animal cell membranes.
Precursor from which other
steroids are made including
hormones.
High levels contribute to
atherosclerosis
Proteins
• Made of C, H, O, N
• Have many functions:
- Control chemical reaction rates – Enzymes
- Form bones and muscles – Structural
- Hemoglobin carries oxygen – Transport
- Fight disease - Antibodies
Proteins
• Are
structurally
diverse
consistent
with their
many
functions.
Proteins
• Amino Acids –
Monomer
• There are 20 amino
acids.
• Proteins are made by
the bonding of some
configuration of the 20
amino acids
Figure 5.16 Making a polypeptide chain
• There are 4 levels
of protein structure:
•Primary
•Secondary
•Tertiary
•Quaternary
Objectives
Topic 2.4: Enzymes
10. Explain how chemical reactions affect
chemical bonds
11. Describe how energy changes affect how
easily chemical reactions will occur.
12. Explain why enzymes are important to living
things.
Vocabulary:
Chemical reaction Activation energy Catalyst
Substrate
Enzyme
Chemical Reaction
• Changes one set of chemicals into another set of chemicals.
• Reactants- enter into chemical reaction
• Products – produced by chemical reaction
• Involves breaking and making of chemical bonds.
Energy
• Energy is released when chemical bonds are broken; reactions occur spontaneously.
• Energy is absorbed when chemical bonds are formed; reactions require additional
energy.
• Living organisms carry out both types of chemical reactions to sustain life ;
metabolism.
Enzymes
• Are catalysts; speed up rate of chemical
reaction.
• Are proteins; biological catalysts.
• Speed up reaction rates by lowering activation
energy.
• Activation energy; the amount of energy
needed to get a chemical reaction started.
• Lowering activation energy makes the reaction
happen faster.
Enzymes
Enzymes
• Enzymes provide site where reactants are
brought together.
• Reactants = substrate
• Substrate binds to active site of enzyme;
enzyme substrate complex
• Reaction occurs.
• Product released; enzyme freed for another
reaction.
Enzymes
Enzymes
• Enzymes are specific; enter into one type of
reaction.
• Enzymes are biological molecules; can be
damaged by changes in pH and temperature