The body breaks down food into nutrient molecules during . digestion absorption salivation peristalsis

The answer is Digestion.

Explanation:

During digestion, enzymes in our body are used to break down large food molecules into smaller molecules for a better absorption. For example, amylase break down carbohydrate, protease break down protein and lipase break down fat.

During exercise, blood pressure, pulse and respiration increase to meet the increased demand for oxygen and nutrients by your musculoskeletal system. The adjustment of vital signs to match your body's level of physical activity is an example of homeostasis in action.