Question

Define mechanical and chemical digestion.

Answer 1

@Alexaalexi

Answer 2

Mechanical Digestion - Food is crushed and liquefied by the teeth, tongue, and peristaltic contractions (waves of involuntary muscle contraction) of the stomach and small intestine. This creates a greater surface area for the digestive enzymes to work upon.

Chemical Digestion - Many glandular structures, dispersed throughout the body, are involved in breaking food into simple molecules that can be absorbed. In the mouth, the salivary glands produce saliva, which both lubricates food and begins the process of starch digestion. Saliva contains salivary amylase (ptyalin), an enzyme that digests starch to maltose (a disaccharide). As food leaves the mouth, the esophagus conducts it to the stomach via the cardiac sphincter by means of peristaltic waves of smooth muscle contraction :D