AP BIOLOGY

Detailed explanation-1: -Chemical digestion involves the secretions of enzymes throughout your digestive tract. These enzymes break the chemical bonds that hold food particles together.

Detailed explanation-2: -Stomach acid is necessary for digestion and absorption of protein, vitamin B12 and several minerals. When your body is no longer able to break down and absorb these nutrients, you end up with undigested food and nutritional deficiencies.

Detailed explanation-3: -The chemical digestion of proteins begins in your stomach. Carbohydrate and lipid digestion continues in the stomach (lipids are the chemical components of fat). Your stomach releases gastric juices that begin to break down all of the food you’ve eaten.

Detailed explanation-4: -Two types of glands exist in the gastric mucosa that aid in chemical digestion: oxyntic glands and pyloric glands. Oxyntic glands are located in the body of the stomach and contain parietal cells and chief cells. Parietal cells secrete hydrochloric acid, concentrated to approximately 160 mmol/L and a pH of 0.8.

Detailed explanation-5: -answer is B. Mechanical digestion alters chemical bonds.