Mechanical digestion begins in the mouth as the food is chewed. Chemical digestion involves breaking down the food into simpler nutrients that can be used by the cells. Chemical digestion begins in the mouth when food mixes with saliva. Saliva contains an enzyme (amylase) that begins the breakdown of carbohydrates. read more
Most chemical digestion, however, occurs within the stomach, with some happening in the intestines. The hydrochloric acid, located in the stomach, works for the purposes of chemical digestion. Chemical digestion is completely invisible. read more
Mechanical digestion occurs in the mouth and stomach, Segmentation is the back and fourth mixing of food in stomach. Chemical digestion occurs in the stomach were Hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum. read more