Question

which of the following statements regarding myosin in skeletal muscle is true? multiple choice myosin cross - bridge heads contain two binding sites, one for actin and one for tropomyosin. myosin is an atpase. the rate of atp hydrolysis by myosin is the same in all types of skeletal muscle. all of the myosin cross - bridge heads in a thick filament are oriented and rotate in the same direction. troponin covers the binding site on myosin molecules until ca²⁺ binds to troponin to remove it from its blocking position.

Explanation:

Myosin is an ATP - ase enzyme. It can hydrolyze ATP to release energy for muscle contraction. Myosin cross - bridge heads have binding sites for actin and ATP, not tropomyosin. The rate of ATP hydrolysis by myosin varies among different types of skeletal muscle fibers. In a thick filament, myosin cross - bridge heads are not all oriented and rotating in the same direction. Troponin binds to tropomyosin and calcium, and tropomyosin covers the binding sites on actin, not myosin.

Answer:

Myosin is an ATPase.