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.

Detailed explanation-2: -Hint: Pepsinogen is inactive form and converted into active form pepsin by the action of HCl, prorenin is also inactive form which is converted by HCl into renin, which acts on milk protein called casein. Both enzymes are secreted by the zymogenic cell.

Detailed explanation-3: -A substance made by cells in the stomach. Acid in the stomach changes pepsinogen to pepsin, which breaks down proteins in food during digestion.

Detailed explanation-4: -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.