Mutations in the gene for troponin can result in the production of the troponin protein, which has varying affinities for Ca²⁺ ions. Suppose that in a muscle cell a mutant troponin is expressed that has such a high affinity for Ca²⁺ ions that once they bind to troponin they cannot unbind. What will likely happen in this muscle cell?
A)Myosin heads will not bind to actin after action potentials stop being received.
B)Myosin heads will bind to actin after action potentials stop being received.
C)Tropomyosin will not move to expose myosin binding sites.
D)Cross-bridges will form between myosin and tropomyosin.

Question

Quizplus · Accepted Answer

If troponin has a high affinity for Ca²⁺ ions and cannot release them, tropomyosin will remain shifted away from the myosin binding sites on actin, allowing myosin heads to continue binding to actin even after action potentials stop.

Mutations in the Gene for Troponin Can Result in the Production