Each myosin head has a binding site for a calcium only b act

Each myosin head has a binding site for:

(a) calcium only.

(b) actin only.

(c) ATP only.

(d) calcium and ATP.

(e) actin and ATP.

Solution

(e) actin and ATP.

Each myosin molecule contains a globular head and tail portion. The binding of ATP (adenosine triphosphate) to the head region of myosin hydrolyses the ATP to ADP (adenosine diphosphate), releasing the phosphate bond; this hydrolysis provides the energy for muscle contraction. Then the thick myosin filaments slide over the thin stationary actin filaments.