Answer:
The protein digestion needs an acid surrounding environment.
Step-by-step explanation:
Protein digestion starts with an enzyme called pepsine, but this enzyme is activated in an acid solution, if there is a neutral or alkaline surrounding solution, it will not activate and the proteins can not be digest or the process will be longer.
The antiacid substance, neutralize the normal acid pH of the stomach, and since the enzyme will not work, the activation energy ( the necessary energy to start a chemical reaction) used to digest the proteins will be higher, because is lack of the helper enzyme.