HUMAN NUTRITION

Detailed explanation-1: -It breaks down proteins into smaller peptides and amino acids that can be easily absorbed in the small intestine. Specific cells within the gastric lining, known as chief cells, release pepsin in an inactive form, or zymogen form, called pepsinogen.

Detailed explanation-2: -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-3: -Parietal cells secrete hydrochloric acid that helps break down food and intrinsic factor that aids in the absorption of vitamin B12. Chief cells secrete enzymes that support digestion. Neuroendocrine cells secrete various hormones that regulate stomach acidity, hunger, and gastrointestinal motility.