What happens when the parietal cells of gut epithelium becomes partially non-functional? The options are a) The pancreatic enzymes will not work properly b) The pH of the stomach will fall abruptly c) Steapsin will be more effective d) Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones. The answer is D because pro enzyme pepsinogen gets converted to active pepsin in presence of HCl. But, Why can't the answer be B ? Because if HCl is not secreted by perital cells then obviously pH of the stomach is going to fall down ?

Parietal cells are responsible for acid secretion (HCl) in the stomach.

pH is inversely correlated to H+ concentration; the higher the H+ concentration, the _lower_ the pH.

If the stomach's parietal cells become partially non-functional, there will be _less_ acid secreted into the stomach (a lower H+), and the pH will _rise_.

Answer (b)

> (b) The pH of the stomach will fall abruptly

is the opposite of what would be expected to occur.

The correct answer is d), for the reason you listed.

> Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.

Regulation of Acid Secretion