In the Mechanism of Chymotrypsin, Which of the Following Amino

Multiple Choice

In the mechanism of chymotrypsin, which of the following amino acids found in the active site is correctly defined in terms of its role in the reaction?

A) serine: hydrogen bonds with carbonyl oxygen to withdraw electron density from the substrate
B) histidine: deprotonates aspartic acid to allow a nucleophilic attack to occur
C) aspartic acid: electrostatic stabilization of histidine to make a stronger base
D) cysteine: performs a nucleophilic attack on the carbonyl carbon of the substrate
E) none of the above