Which enzyme is primarily responsible for degrading the neurotransmitter acetylcholine in the synaptic cleft?

• A. Choline acetyltransferase
• B. Monoamine oxidase
• C. Acetylcholinesterase
• D. Catechol-O-methyltransferase

Answer: (C)

Verified step by step guidance

1. Understand the role of acetylcholine in neurotransmission: Acetylcholine is a neurotransmitter that transmits signals across the synaptic cleft between neurons.
2. Identify the enzymes listed and their functions: Choline acetyltransferase synthesizes acetylcholine, monoamine oxidase degrades monoamine neurotransmitters, and catechol-O-methyltransferase degrades catecholamines.
3. Recall that the enzyme responsible for breaking down acetylcholine in the synaptic cleft is acetylcholinesterase, which rapidly hydrolyzes acetylcholine to terminate the signal.
4. Recognize that acetylcholinesterase's activity ensures that acetylcholine does not accumulate in the synaptic cleft, allowing proper regulation of neurotransmission.
5. Conclude that among the options, acetylcholinesterase is the primary enzyme responsible for degrading acetylcholine in the synaptic cleft.