Salivary amylase is an enzyme found in the mouth. it speeds up the reaction of breaking down starch into sugars. why will salivary amylase only speed up the break down of carbohydrates and not proteins? options: (a) the enzyme is the wrong substrate for proteins. (b) proteins will not fit into the active site of the amylase enzyme. (c) proteins will never get broken down into smaller molecules like carbohydrates.

The correct answer would be (B) Proteins will not fit into the active site of the amylase enzyme.  

Enzymes are biocatalyst which accelerates the rate of a biochemical reaction.

They are highly specific to their substrate.

This high specificity is obtained with the help of the active site.  

Every enzyme has the active site in which a particular substrate can fit or bind.

Similarly, salivary amylase also contains an active site which is specific for the polysaccharides like starch.  

Proteins are not able to fit or bind to this active site due to which they are digested through amylase.