The contents of gastric juice include mucus, hydrochloric acid, electrolytes, enzymes, intrinsic factor and water. This juice helps break down food before it moves into the small intestine.
When food enters the stomach, it mixes with gastric juice. The hydrochloric acid in the juice breaks down food and kills microorganisms. It also converts pepsinogen into pepsin. Pepsin is responsible for breaking down proteins.
The mucus present in gastric juice protects the stomach from the acidity of pepsin and hydrochloric acid. The presence of hydrochloric acid keeps the pH of the stomach at approximately 2.0, according to Dr. Michael Gregory of Clinton Community College. Intrinsic factor is necessary for absorbing vitamin B-12.