Answer:
-- the active site contains a serine residue, an unprotonated histidine, and an unprotonated aspartate residue at pH 7.0 prior to binding the substrate.
-- attack of a water molecule on the acyl-enzyme intermediate yields the second product.
-- an acetyl-enzyme intermediate forms during the mechanism.
Explanation:
p-Nitrophenyl acetate is a chemical compound and is used as a substrate in the assays for esterase as well as lipase activity.
Doing hydrolysis of the p-nitrophenyl acetate releases a p- nitrophenol, and its absorbance can be monitored at about 405 nm.
In doing hydrolysis of the p-nitrophenyl acetate by a chymotrypsin, the following holds true :