Cardiac myosin has a high affinity for actin when the myosin has what molecule(s)bound to it?
A) Calcium
B) ATP
C) ADP and phosphate
D) Creatine phosphate

Question

Quizplus · Accepted Answer

The affinity of the myosin head for actin depends on whether ATP is bound or ADP and phosphate are bound.Free myosin heads bind ATP and hydrolyze it to ADP and phosphate.Calcium ions are needed for muscle contraction.Myosin has a high affinity for actin when ADP and phosphate are bound,and low affinity when ATP is bound.When there is an excess of ATP,myocardial cells transfer energy to a storage form called creatine phosphate.

Cardiac Myosin Has a High Affinity for Actin When the Myosin