Why does action of salivary amylase stop in the stomach?

Question

Why does action of salivary amylase stop in the stomach?

Answer 1

all enzymes are proteins, to work, proteins need to maintain a correct shape. the proteins shape is maintained at a certain optimum pH and beyond this pH the protein changes shape and is denatured. therefore the enzyme loses its shape and is unable to bind the substrates as they cannot fit into it anymore. the pH of the mouth is significantly higher than that of the stomach which is higly acidic and causes denaturation of the enzyme. therefore it cannot work anymore.

Answer 2

Because salivary amylase is only present in the saliva in the mouth. But sometimes, we gulp some parts of it, that it is eventually counteracted by the acidity of the stomach.

Answer 3

The acidity of the stomach causes the denaturation of salivary amylase, deactivating it.

Answer 4

Salivary amylase's optimum pH is 7, the pH of the mouth. The HCl in the stomach lowers the pH to pH 2 - 3 which it outwith the working range of salivary amylase.

Hope this helps!