Which of the Following Regarding the Hydrolysis of P-Nitrophenyl Acetate

Multiple Choice

Which of the following regarding the hydrolysis of p-nitrophenyl acetate by chymotrypsin is correct?

A) The active site contains a serine residue,an unprotonated histidine,and an unprotonated aspartate residue at pH 7.0 prior to binding the substrate.
B) The first product is acetic acid.
C) An actyl-enzyme tetrahedral intermediate forms during the mechanism.
D) Attack of a water molecule on the acyl-enzyme intermediate yields the first product.