In the stomach, parietal cells produce hydrochloric acid, which is needed to convert the proenzyme pepsinogen to the protein-digesting enzyme pepsin. Hydrochloric acid dramatically lowers the pH of the stomach contents to around 2.5. When saliva is swallowed will amylase continue to be functional when it enters the stomach?

No, it will not function.

Explanation: The gastric acid in the human stomach lumen generally has a pH level of about 1.5 to 3.5 as more hydrochloric acid is been released in the stomach.

Amylase is an enzyme secreted ino the silva in our mouth, this enzyme helps to accelerate reactions such as breaking down of starch into sugar in an optimum pH which is about 5.2 to 7.0.

When amylase enters the stomach, it cease to function because the pH level of gastric acid in the stomach lumen is between 1.5 to 3.5 (acidic) which is not favourable to the enzyme. This condition limits the amylase from forming enzyme-substrate complexes with starch.

So with the pH of the stomach contents at around 2.5, the amylase will not function when it enters the stomach.