Nutrition And Digestion

Front 1

what do animals use food for?

Back 1

energy sources (for making ATP; maintenance)

raw materials (for making new tissues: growth or reproduction)

Front 2

macronutrients

Back 2

(needed in relatively large qualities)

energy sources and building materials (structural)

proteins

lipids

carbohydrates

Front 3

micronutrients

Back 3

(needed in relatively small quantities)

often catalytic, some structural

inorganic minerals

organic vitamins

Front 4

categories of vitamins

Back 4

water soluble (B,C, niacin, folic acid, etc.)

lipid soluble (A, D, E, K)

Front 5

undernourishment

Back 5

lack of sufficient caloric intake (less chemical potential energy obtained than necessary)

(starvation if condition persists)

Front 6

deficiency diseases

Back 6

lack of adequate amounts of essential amino acids, fatty acids, vitamins, or mineral in the diet

(malnourishment)

ex. Kwashiorkor, Scurvy, Goiter

Front 7

vitamin dosages

Back 7

recommended dietary allowances of vitamins ("RDA") should keep you healthy; easily obtained in a balanced diet

Front 8

digestion

Back 8

breaks food down into monomers

this occurs in the gut lumen and is external to the body

Front 9

absorption

Back 9

monomers are absorbed across the gut epithelium and into the body

Front 10

salivary gland functions

Back 10

lubrication

moistening

initial carbohydrate digestion (salivary alpha-amylase): chemical breakdown

Front 11

how do digestive enzymes work?

Back 11

hydrolysis of substrates

chemical addition of water to break substrate macromolecules into smaller subunits

lipids ---> fatty acids

proteins--->amino acids

carbohydrates---> simple sugars

Front 12

peristalsis

Back 12

a wave of circular contraction of muscle lining the gut, moving in one direction to push a bolus of food along

Front 13

basic digestive tract function

Back 13

storage

mechanical breakdown

chemical digestion : high acidity, peptidases

absorption

Front 14

How does the digestive tract avoid digesting itself?

Back 14

-secretion of digestive enzymes as inactive zymogens

-'armor': thick protective layer of mucus

-rapid replacement of epithelial cells

Front 15

pancreas

Back 15

major source of digestive enzymes

produces lots of bicarbonate; changes pH in gut from highly acid (stomach) to basic

Front 16

digestive enzymes

Back 16

proteases

amylases

lipases

nucleases

complete the breakdown of food into absorbable monomers

Front 17

When is active transport (energy cost) required?

Back 17

is always necessary when substances are moved against concentration gradients

Front 18

coprophagy

Back 18

in rabbits, some rodents

two kinds of 'pellets' produced: one is consumed, one is not

Front 19

general digestion qualities of herbivores

Back 19

-can digest low-quality food

-they have to 'pay' their symbionts a portion of the food energy

-they have long transit time

-low digestive 'efficency'

-they may be limited by processing time

Front 20

general digestion qualities of carnivores

Back 20

rapid digestion (unless meal is really big)

high digestive efficiency (little is wasted)