Gastric juice composition and functionPepsinogen is converted to pepsin, which digests proteins. Pepsinogen production is stimulated by the presence of gastrin in the blood .HClHydrochloric acid (HCl) converts pepsinogen to pepsin which breaks down proteins to peptides. HCl maintains a pH in the stomach of approximately 2.0.It also dissolves food and kills microorganisms.Mucous protects the stomach from HCl and pepsin.Secretion of Gastric JuiceSeeing, smelling, tasting, or thinking about food can result in the secretion of gastric juice.Gastrin is a hormone that stimulates the stomach to secrete gastric juice.
