MUSCLE PHYSIOLOGY

Detailed explanation-1: -ATP binding causes the myosin head to detach from the actin (Figure 4d). After this occurs, ATP is converted to ADP and Pi by the intrinsic ATPase activity of myosin. The energy released during ATP hydrolysis changes the angle of the myosin head into a cocked position (Figure 4e).

Detailed explanation-2: -One part of the myosin head attaches to the binding site on the actin, but the head has another binding site for ATP. ATP binding causes the myosin head to detach from the actin.

Detailed explanation-3: -ATP is necessary to detach the myosin head from the actin filament. Without ATP present, the myosin head remains bound and the contraction is sustained.

Detailed explanation-4: -The Muscular System 5.9). ADP is then dissociated from the myosin molecule, and the myosin head (the cross-bridge) remains firmly attached to actin. This condition persists until a new molecule of ATP binds to the myosin head, causing it to be released from the actin filament.