Question

In the hydrolysis of p-nitrophenylacetate by chymotrypsin all of the following are correct (mark all the correct answers): Group of answer choices 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. the first product is acetic acid. an acetyl-enzyme intermediate forms during the mechanism.

Answer 1

-- 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.

Step-by-step 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 :

• By hydrolysis, the acetyl enzyme intermediate is formed.
• an attack of the water molecule on acyl enzyme yields a second product
• the site consists of a serine residue, unprotonated aspartate and an unprotonated histidine residue at pH