Acetylcholine is a neurotransmitter that initiates muscle contraction.In order for muscle to relax after contraction, acetylcholine must be broken down into choline and acetate by the enzyme acetylcholinesterase.Nerve agents such as Sarin inhibit acetylcholinesterase by permanently covalently bonding to a serine amino acid in the active site of the enzyme, causing muscle paralysis.What type of inhibitor is Sarin?
A) a competitive, reversible inhibitor
B) a noncompetitive, reversible inhibitor
C) a competitive, irreversible inhibitor
D) a noncompetitive, irreversible inhibitor
E) Sarin is not an inhibitor.

Question

Quizplus · Accepted Answer

Sarin is a competitive, irreversible inhibitor because it binds covalently to the active site of acetylcholinesterase, preventing acetylcholine from accessing its site of action and thus inhibiting the enzyme's activity permanently unless the enzyme is regenerated or new enzymes are synthesized.

Acetylcholine Is a Neurotransmitter That Initiates Muscle Contraction