Assertion : Presence of HCl in stomach is necessary for the process of digestion.
Reason : HCl kills and inhibits the growth of bacteria in the stomach.
Presence of hydrochloric acid in stomach is necessary for digestion because acidic medium activates the action of gastric juice. HCl maintains a strong acidic pH of about 1-2 in the stomach. At this acidic pH inactive pepsinogen is spontaneously hydrolysed to active pepsin and inactive pro-rennin is convert to active rennin. Pepsin and rennin digest proteins to peptones and proteoses. In addition, HCl helps to kill and inhibit the growth of bacteria and other harmful organisms that may enter in the stomach along with the food.