USDA Food Guide The USDA Food Guide assigns foods to five major groups

FRUITS

VEGETABLES

GRAINS

MEAT, POULTRY, FISH, LEGUMES, EGGS, AND NUTS

MILK, YOGURT, AND CHEESE

OILS SOLID FATS AND ADDED SUGARS

Estimated Daily kCalorie Needs for Adults

Food must first be

digested and

absorbed before

the body can use it.

Summary of Digestive Secretions

and Their Major Actions

Absorption of Nutrients

Absorption of nutrients into

intestinal cells typically

occurs by simple diffusion,

facilitated diffusion, or active

transport.

The Small Intestinal Villi

Absorption of nutrients into

intestinal cells typically occurs by

simple diffusion or active transport.

Vascular System

The Liver

Hydrolysis of a Disaccharide

A glycogen molecule contains

hundreds of glucose units in

highly branched chains. Each

new glycogen molecule needs a

special protein for the attachment

of the first glucose (shown here

in red).

A starch molecule

contains hundreds of

glucose molecules in

either occasionally

branched chains

(amylopectin) or

unbranched

chains (amylose).

Absorption of Monosaccharides

Maintaining Blood Glucose Homeostasis