Answer:
The active site residues include Serine, Histidine and Aspartatic acid
Step-by-step explanation:
The catalytic triad at the active site of Chymotrypsin includes Ser-105 (Serine), His-57 (Histidine) and Asp-102 (Aspartic acid).
His-57: Deprotonates and polarizes Ser-105 so that it is able to react with substrate.
Asp-102: The carboxyl group of Asp-102 hydrogen bonds with the R-group of the His-57 which facilitates the deprotonation of Ser-105.
Ser-105: The strong nucleophile of serine attacks the substrate leading to hydrolysis.