Question

What enzyme catalyzes breakdown of catecholamines in the synaptic cleft only ______.

A) choline acetyl transferase
B) catechol-O-methyltransferase
C) monoamine oxidase
D) adenylate cyclase
E) acetylcholinesterase

Answer 1

Monoamine oxidase (MAO) is the enzyme that catalyzes the breakdown of catecholamines such as epinephrine and norepinephrine in the synaptic cleft, not acetylcholinesterase which breaks down acetylcholine.

Step-by-step explanation:

The enzyme that catalyzes the breakdown of catecholamines, which are neurotransmitters like epinephrine and norepinephrine, within the synaptic cleft is monoamine oxidase (MAO).

This enzyme is responsible for deaminating neurotransmitters, which means it removes an amino group from the molecule, leading to its inactivation and breakdown. This process is essential for the regulation of neurotransmitter levels in the synaptic cleft and ensures that signals are properly terminated after their transmission. While acetylcholinesterase breaks down acetylcholine (ACh), it is not responsible for the breakdown of catecholamines.

Answer 2

The enzyme catechol-O-methyltransferase (COMT) is responsible for catalyzing the breakdown of catecholamines in the synaptic cleft. Acetylcholinesterase (AChE) breaks down acetylcholine, not catecholamines, making COMT the correct answer.B) catechol-O-methyltransferase.

Step-by-step explanation:

The enzyme that catalyzes the breakdown of catecholamines in the synaptic cleft is catechol-O-methyltransferase (COMT).

Catechol-O-methyltransferase specifically targets catecholamines, such as dopamine, norepinephrine, and epinephrine, by transferring a methyl group to them, which makes them more water-soluble and thus easier to be excreted from the body.

Acetylcholinesterase (AChE), on the other hand, is responsible for the breakdown of the neurotransmitter acetylcholine into choline and acetate.