24 terms

ap nutrition

ap nutrition
1. All chemical reactions in body
2. Anabolism = synthesis and energy storage reactions
3. Catabolism = energy liberating reactions
synthesis and energy storage reactions
energy liberating reactions
1. Polysaccharides - complex carbohydrates, starch, fiber
2. Disaccharides
3. Monosaccharides
a. Glucose - primary source of energy
b. Galactose - converted by liver to glucose
c. Fructose - used by sperm, converted by liver to glucose
Carbohydrate Metabolism
C6H12O6 + O2 ---> CO2 + H2O + energy (heat + ATP)
1. Glycolysis
2. Krebs cycle
3. Electron Transport System (Oxidative Phosphorylation)
Carbohydrate Metabolism: Glycogenesis
1. Excess glucose glycogen in liver and muscle
2. Glycogen in liver - maintains blood glucose levels
3. Glycogen in muscle - used by the muscle for energy
Carbohydrate Metabolism: Glycogenolysis
1. Glycogen ---> glucose
2. Controlled by glucagon
3. Releases glucose to increase blood glucose levels
Carbohydrate Metabolism: Gluconeogenesis
1. Production of glucose from alternate sources
2. Can be formed from lactic acid, amino acids
Carbohydrate Metabolism: Lipogenesis
Production of fat from carbohydrates, proteins & fats
Lipid Metabolism: Lipids
1. Triglycerides
2. Phospholipids
3. Cholesterol
Lipid Metabolism: Essential Fatty Acids
1. Required in the diet
2. Linoleic acid = Omega-6 fatty acid
3. Alpha-linolenic acid = Omega-3 fatty acid
Lipid Metabolism: Lipid catabolism
1. Energy
2. Produces more energy than carbohydrates
3. Without carbohydrates ketone bodies (ketogenesis)
Lipid Metabolism: Lipid anabolism (lipogenesis)
Lipid Metabolism
Uses fatty acids to synthesize other lipids.
Lipid Transport
1. Requires carrier molecules - lipoproteins
2. Chylomicrons - carry lipids from intestine to liver
3. LDL (Low density lipoprotein)
a. Carries lipids, particularly cholesterol from liver to cells
b. AKA "Bad cholesterol"
4. HDL (High density lipoprotein)
a. Carries cholesterol from cells to liver for disposal
b. AKA "Good cholesterol"
Protein Metabolism: Protein anabolism
1. Most important
2. Structural, hormones, enzymes, transport molecules
3. 8-9 essential amino acids
Protein Metabolism: Protein catabolism
1. Energy
2. Protein balance - amount of protein ingested versus the amount of protein used
3. Nitrogen balance - amount of nitrogen ingested compared to amount of nitrogen excreted
a. Positive nitrogen balance - growth
b. Negative nitrogen balance - wasting
Protein Metabolism: Gluconeogenesis
Requires deamination
Amine group converted to urea
Fat soluble - dissolves in fat
Stored in the body
Possibly toxic
Requires bile for absorption
Vitamins A, D, E, and K
Water soluble - dissolves in water
Not stored in body
Seldom toxic
B complex vitamins and vitamin C
Serve as coenzymes
Essential - must be obtained from diet
Some Vitamin D can be synthesized in skin
1. Inorganic elements or salts found in the earth
2. Essential - must be obtained from diet
3. Serve as Cofactor
4. Electrolytes
5. Examples - iron, iodine, potassium, sodium, calcium, etc.
Metabolic Rates: Basal metabolic rate
1. Energy required for activities of life
2. Controlled by thyroid hormone
3. Higher in men than women
4. Decreases with age
Metabolic Rates: Total metabolic rate
Combination of basal metabolic rate, energy for voluntary activities and energy to digest food
Metabolic Rates: Energy balance and weight
1. Energy in = energy out ENERGY BALANCE - constant wt.
2. Energy in > energy out EXCESS ENERGY = wt. gain
3. Energy in < energy out ENERGY DEFICIT = wt. loss
Mechanisms for Regulating Food Intake
1. Appetite center
a. Located in hypothalamus
b. Learned behavior
2. Satiety center
a. Located in hypothalamus
b. Senses fullness - stop eating