What function does the low pH of the stomach serve?

a) It allows gastric enzymes to work.
b) The acidic conditions break down foods directly.
c) It allows for the activation of pepsinogen into pepsin.
d) All of these choices are correct.

b) The acidic conditions break down foods directly.

c) It allows for the activation of pepsinogen into pepsin.

Explanation:

The acid inactivates all the enzymes in the food, and begins its own function of breaking down what is left of the food in combination with the enzyme pepsin. Finally, this nutrient rich food concentrate moves in the small intestine. There the acid is neutralized and enzymes produced by the pancreas are reintroduced to complete the process.

All of these choices are correct-d

Explanation:

Low pH of the stomach is effective because enzymes like Pepsin, break down food and work best in an acidic environment in the breakdown of proteins Also, a  low pH stomach acid also triggers  the release of other digestive enzymes from the pancreas, which also help break down carbohydrates,

The mechanism is such that Because most proteins start digestion in the stomach, the stomach cells secretes the zymogen pepsinogen  which by activation by HCl in the stomach forms the Pepsin that break the peptide bond of amino acids helping digestion.

Low pH in the stomach, ie  Gastric acid with a pH of less than 3  provides an unsuitable environment for for bacteria and parasites by killing them and preventing them from reaching the intestines which would have been responsible for  many more illnesses.