Q. 22 - Biology

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

Step-by-Step Solution

Answer

The correct answer is option (d)

Acetylcholinesterase activity aids in the removal of this neurotransmitter. 

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.
• Acetylcholine is broken down, ending the neurotransmission process.
• 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.