| A | B |
|---|
| nutrient | a substance in food that produces energy and materials for life activities |
| carbohydrate | a nutrient that provides most of the body's energy; made up of carbon, hydrogen, and oxygen |
| protein | a nutrient made up of amino acids; used throughout the body for growth and to replace and repair cells |
| amino acids | the building blocks of protein |
| fat | a nutrient that provides energy; also cushions organs and helps the body absorb some vitamins |
| vitamin | organic nutrients that promote growth, regulate body functions, and help the body use other nutrients |
| mineral | inorganic nutrients that regulate many chemical reactions in the body, such as building cells and sending nerve impulses |
| food group | a group of foods containing the same nutrients; for example, the bread and cereal group |
| antioxidant | a substance that prevents chemicals that enter the body from reacting with oxygen; may stop or prevent cancer |
| digestion | the process that breaks down food into small molecules that can be moved into the blood and used by the cell |
| mechanical digestion | physical breakdown of food into smaller particles by chewing (in the mouth) and by churning (in the stomach) |
| chemical digestion | chemical break down of food by fluids in the mouth, stomach, and small intestine; breaks down large molecules into smaller ones that can be absorbed by cells |
| saliva | the watery substance produced in the mouth that begins the chemical digestion of food |
| peristalsis | muscular contractions that move food through the digestive system |
| chyme | the thin, watery liquid in the digestive tract; partially digested food |
| villi | tiny, fingerlike projections on the inner surface of the small intestine |
