Question

The event which removes the regulatory proteins from the binding site of actin is which of the following?

A) action potential along the sarcolemma
B) binding of Ca2+ by the regulatory proteins
C) binding of neurotransmitter at the motor end-plate
D) depolarization of the T-tubules.

Answer 1

The correct answer will be option-B.

Step-by-step explanation:

The contraction of the muscle is caused by the slipping of thick filament myosin and thin filament called the action. The myosin is a motor element which causes the sliding by binding to the myosin-binding sites present in the actin.

The binding site is covered by the regulatory protein called tropomyosin and troponin. The Ca⁺² ions produced by the sarcolemma binds to the troponin which shifts the tropomyosin to another side from myosin binding site. This shift allows the myosin to bind at the actin.

Thus, Option-B is the correct answer.