<P> The highly acidic environment in the stomach lumen causes proteins from food to lose their characteristic folded structure ( or denature ) . This exposes the protein 's peptide bonds . The gastric chief cells of the stomach secrete enzymes for protein breakdown ( inactive pepsinogen , and in infancy rennin ) . Hydrochloric acid activates pepsinogen into the enzyme pepsin , which then helps digestion by breaking the bonds linking amino acids , a process known as proteolysis . In addition , many microorganisms have their growth inhibited by such an acidic environment , which is helpful to prevent infection . </P>
what is the role of hcl in the stomach
activates pepsinogen into the enzyme pepsin , which then helps digestion by breaking the bonds linking amino acids , a process known as proteolysis