Question

The muscle relaxes if no new nerve signal arrives. However the neurotransmitter from the previous stimulation is still present in the synapse. The activity of ________ helps to remove this neurotransmitter.

1. myosin
2. action potential
3. tropomyosin
4. acetylcholinesterase

Short answer

The correct answer is option (d)

Acetylcholinesterase activity aids in the removal of this neurotransmitter.

Step-by-step solution

Acetylcholinesterase

• The main cholinesterase in the body is acetylcholinesterase, commonly referred to as AChE, AChase, or acetylhydrolase.
• When acetylcholinesterase is secreted by the muscle, collagen linked to the basal lamina keeps it bound to the muscle.

Step: 1 Explanation for Correct answer

• The synapse between nerve cells and muscle cells is where acetylcholinesterase is present. After a signal is passed, it waits patiently and quickly takes action.
• Acetylcholineisbrokendown,endingtheneurotransmissionprocess.
• This enzyme degrades acetylcholine and stops a single nerve impulse from generating multiple action potentials. Thus, the option d is the correct answer .

Step: 2 Explanation for incorrect answer

• Myosin attaches to actin after the myosin-binding sites are accessible, and if there is enough ATP, cross-bridge cycling can start. So, option a is wrong.
• Nerve signals known as action potentials. In order to deliver these signals to the target tissues, neurons produce and carry them along their processes. So, option b is wrong as well.
• Tropomyosin binds to actin during a typical muscle contraction. The myosin head's ability to connect to actin is blocked, which limits muscle contraction. Hence, option c is wrong too.