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: -chyme, a thick semifluid mass of partially digested food and digestive secretions that is formed in the stomach and intestine during digestion. In the stomach, digestive juices are formed by the gastric glands; these secretions include the enzyme pepsin, which breaks down proteins, and hydrochloric acid.

Detailed explanation-3: -Final answer: In the human digestive system, the enzymes pepsin and trypsin are secreted by the stomach and pancreas respectively.

Detailed explanation-4: -Pepsin is the mature active form of the zymogen (inactive protein) pepsinogen. Pepsin was first recognized in 1836 by the German physiologist Theodor Schwann. In 1929 its crystallization and protein nature were reported by American biochemist John Howard Northrop of the Rockefeller Institute for Medical Research.