Question

The acetyl group in aspirin acts on _____ enzymes, by _____ binding to serine.

a) COX-1, covalent
b) COX-2, reversible
c) Lipase, non-covalent
d) Amylase, allosteric

Answer 1

a) COX-1, covalent

Aspirin inactivates COX-1 and COX-2 enzymes through covalent bonding to serine, which irreversibly inhibits the enzymes and impairs prostaglandin production.

Step-by-step explanation:

The acetyl group in aspirin acts on the cyclooxygenase enzymes, specifically COX-1 and COX-2, by covalent binding to serine residues within these enzymes.

This action inactivates the enzymes, preventing the conversion of arachidonic acid to prostaglandins and thus reducing pain and inflammation.

Aspirin is known for its ability to irreversibly inhibit the enzyme, differentiating it from other NSAIDs that may inhibit COX enzymes reversibly.