Why does calcium not bind to calmodulin in a non-stimulated cell?
A)Calmodulin's affinity for calcium ions is too low to allow binding in a nonstimulated cell.
B)Calmodulin's affinity for calcium ions is too high to allow binding in a nonstimulated cell.
C)In a nonstimulated cell, calcium ions are destroyed.
D)In a nonstimulated cell, calcium ions are produced.
E)In a nonstimulated cell, calcium ions preferentially bind to another protein in the cytosol.

Question

Quizplus · Accepted Answer

Calmodulin's affinity for calcium ions is regulated by the intracellular calcium concentration. In a non-stimulated cell, the intracellular calcium concentration is low, and therefore, the affinity of calmodulin for calcium ions is also low. As a result, calcium does not bind to calmodulin in a non-stimulated cell.

Why Does Calcium Not Bind to Calmodulin in a Non-Stimulated