THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Pepsin is a stomach enzyme that serves to digest proteins found in ingested food. Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen. Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin.

Detailed explanation-2: -Pepsin /ˈpɛpsɪn/ is an endopeptidase that breaks down proteins into smaller peptides. It is produced in the gastric chief cells of the stomach lining and is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food.

Detailed explanation-3: -Pepsin is a chain protein (monomer) composed of two similar folding domains separated by a deep cleft. The catalytic site of pepsin is formed at the junction of the domain, each domain contains two aspartic acid residues, Asp32 and Asp215.

Detailed explanation-4: -Glands in the mucous-membrane lining of the stomach make and store pepsinogen. Impulses from the vagus nerve and the hormonal secretions of gastrin and secretin stimulate the release of pepsinogen into the stomach, where it is mixed with hydrochloric acid and rapidly converted to the active enzyme pepsin.