Question

If a disorder limits the number of calcium ions that combine to actin, what would happen to the sarcomere? A) The myosin and actin would not separate, and the sarcomere would be unable to contract. B) The myosin and actin would not separate, and the sarcomere would remain contracted. C) The myosin and actin will not connect, and the sarcomere would remain contracted. D) The myosin and actin would not connect, and the sarcomere would be unable to contract.​

Answer 1

Option D: The myosin and actin would not connect, and the sarcomere would be unable to contract.

Step-by-step explanation:

Muscle contraction takes place by sliding interaction and cross-bridge formation of the muscle filaments – actin and myosin present in the muscle fibers or sarcomeres. This interaction is called a sliding filament theory.

Calcium is one of the main co-factors which regulate muscle contraction and relaxation. The two proteins which regulate muscle contraction – troponin, tropomyosin- require calcium to function.

Calcium acts along with troponin to facilitate binding of actin and myosin. When there is a lack of calcium, the binding of myosin and actin does not happen and the sarcomere cannot contract.