ANATOMY

Detailed explanation-1: -Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells. The main chemical activity of the stomach is to begin the digestion of proteins. The major role of absorption in the ileum is to reclaim bile salts to be recycled back to the liver.

Detailed explanation-2: -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-3: -Pepsinogen is a powerful and abundant protein digestive enzyme secreted by the gastric chief cells as a proenzyme and then converted by gastric acid in the gastric lumen to the active enzyme pepsin. The role of pepsin and its precursor in protein digestion was first described in the 19th century.

Detailed explanation-4: -Pepsinogens, precursors of pepsins (potent and abundant digestive enzymes that are the primary products of the gastric chief cells), are members of the family of aspartic proteases.

Detailed explanation-5: -A substance made by cells in the stomach. Acid in the stomach changes pepsinogen to pepsin, which breaks down proteins in food during digestion.