What is the role of the acid in our stomach?
Stomach cells secrete Hydrochloric acid. Following are the roles it plays in digestion:
A. Denaturation of protein: Acid cause loosening of the highly folded structure of a protein. The process is called denaturation. Denaturation exposes the peptide bonds to pepsin enzyme, which break the peptide bonds to amino acids.
B. Activation of pepsin: Pepsin is released in its inactive form "pepsinogen." The acid converts them into active form to "pepsin."
Apart from these two it also has defence role in immunity. As acidic medium kills microorganism which may have come with foods.
How the stomach protects itself from the action of acids and pepsin?
Stomach cells secrete a sticky and slippery substance, called mucus. Mucus adheres itself to the mucosal layer. It is resistant from the action of acids and pepsin.
Sometimes mucus itself is not able to protect the mucosa. It can happen due to the use of oily and spicy food, higher secretion of the stomach acids and some diseases like H. pylori infection. In such condition wound like structure form in the lining. Which we call ulcer.
Our body also produces more acids if we eat protein foods. So during the treatment of ulcer, we should consume foods which are low in protein.