Trypsin and Elastase Are Both Enzymes That Catalyze Hydrolysis of Peptide

Multiple Choice

Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds.However, trypsin only hydrolyzes peptide bonds next to lysine, and elastase only hydrolyzes peptide bonds next to alanine.Why?

A) Trypsin is a protein, and elastase is not.
B) The Gs for the two reactions are different.
C) The shapes of the active sites for the two enzymes are different.
D) One of the reactions is endergonic and the other is exergonic.
E) Hydrolysis of lysine bonds requires water; hydrolysis of alanine bonds does not.