Chapter 24 Nutrition Metabolism and Energy Balance Flashcards
Nutrient
Substance in food needed for growth, maintenance, repair
Macronutrient
Major nutrients that make up the bulk of ingested food
3 Types of Macronutrients
Carbohydrates Proteins Lipids
Essential Nutrient
Nutrients that must be eaten because body cannot synthesize these from other nutrients
Example: Fatty acids, amino acids, vitamins
Energy Value (Kilocalories)
1 cal = A calorie is the amount of heat needed to raise temperature of 1 kg H20 by I C
Water Soluble Vitamins
Complex B and Vitamin C
Fat Soluble Vitamins
Vitamin A D E K
Calories per nutrient
Carbohydrates = 4 cal per gram Lipids = 9 cal per gram Proteins = 4 cal per gram
494
Metabolism
Sum of all biochemical reactions involving nutrients
Anabolism (Build) + catabolism (break) = metabolism
3 Stages of Metabolism
- GI tract
- Tissue Cells
- Mitochondria
Complex Carbohydrate
Starches (bread, pasta etc) Long chains and Long term energy
Simple Carbohydrate
Sugars (candy, fruit etc) eratic blood glucose levels spike and doesnt maintain homeostasis (short term energy)
Carbohydrates uses in body
Glucose (fuel) Excess glucose (stored fat) Fructose and galactose (monosaccharides) converted to glucose by liver before entering circulation Disaccharides (sucrose, lactose, maltose)
Glucose
fuel most used by cells to convert to ATP. Cells use fat for energy. Neurons die quickly without it.
Glycolysis
glucose is converted to pyruvic acid
Glycogenesis
polymerizes glucose from glycogen
Glycogen —-> Glucose
Glycogenolysis
hydrolyzes glycogen to glucose monomers
Gluconeogenesis
forms glucose from noncarbohydrate precusors
Lipids
from animal sources (meat and dairy products) and plant sources (nuts and seed oils).
3 Types: Linolein Acid (Omega 6), Linolenic (Omega 3) and Cholesterol
Intake: 20 -35% caloric intake
Two fatty acids (lipids) that the Liver cannot synthesize
Linoleic (omega 6) and linolenic acid (omega 3)
Lipids uses in body
- fatty deposits in adipose tissue (body fat) provide: protection, insulation, storage
- phospholipids are an integral component of myelin sheath and cellular membranes
- cholesterol stabilizes membranes and precursor of bile salts, steroid homrones
- prostaglandins for smooth muscle contraction, BP control, inflammation
- major fuel for hepatocytes and skeletal muscle
3 Types of Lipid Reaction
Beta Oxidation, Lipogenesis, Lipolysis
Beta Oxidation
converts fatty acids to acetyl CoA
Lipogenesis
froms lipids from acetyle CoA and glyceraldehyd 3 - phosphate