Question

The enzyme required for the conduction of nerve impulses across synapse is

• A. Peroxidase
• B. Choline acetylase
• C. Ascorbic acid oxidase
• D. Succinic dehydrogenase

Answer 1

The correct option is B Choline acetylase

Neuromuscular junction transmission begins when an impulse reaches the motor end plate. The arrival of this impulse causes the release of acetyl choline into the synaptic cleft. Here the ACh binds with receptor sites, causing the opening of both $N{a}^{+}$ and $K^{+}$ channels. $N{a}^{+}$ diffuses inward while $K^{+}$ diffuses outward. Because the increase in $N{a}^{+}$ permeability is greater than for $K^{+}$ and because $N{a}^{+}$ is driven by both a chemical and electrical gradient, there is a net movement of positive charges into the cell, causing it to depolarize from its normal resting state of approximately -85 mV. Once the membrane starts to depolarize, its potential is now called an end plate potential (EPP).