Ch. 24 - Metabolism

what are nutrients?

anything the body uses for growth, repair, and maintance

macronutrients

carbs, lipids, protiens

micronutrients

vitamins and minerals

carb sources

mostly plants, dairy (lactose), meats (glycogen)

uses of carbs

1. ATP prod

2. nucleic acid synthesis w pentose sugars

3. glycocalyx fromation*

complex carbs

grains, plant-based, unprocessed, nutrient-rich

empty carbs

processed sugars (soda, candy, etc)

lipid sources

triglycerides and cholesterol

types of triglycerides

saturated and unsaturated

saturated triglycerides

meat, dairy, margarine, etc

unsaturated triglycerides

nuts, seeds, olive oil, etc

cholesterol

85% produced by liver, 15% from meat, eggs, dairy, etc

lipid uses

1. build adipose tissue

2. phospholipids for cell membranes

3. bile salts, steroid hormones, and other molecules

4. absorbing fat-soluble vitamins

lipid requirements

20-35% total daily intake

protein sources

complete and incomplete

complete proteins

meet body’s amino acid requirements (ex. egg, meat, diary, fish, soybeans)

incomplete proteins

short 1 or more amino acid (ex. seeds, nuts, legumes)

protein uses

1. structural molecules (ex. keratin, collegen, elastin, muscle proteins)

2. functional molecules (ex. enzymes, hormones)

protein requirements

~0.8 g protein/kg body weight

nitrogen balance

rate of protein synthesis = rate of protein breakdown in the body

positive nitrogen balance

protein synthesis > protein breakdown (ex. growing kids, pregnancy, tissue repair; replacing proteins)

negative nitrogen balance

protein breakdown > protein synthesis (ex. stress, starvation, low protein intake)

vitamins