MUSCLE PHYSIOLOGY

Detailed explanation-1: -The myosin head then rebinds at a new position on the actin filament, resulting in the release of ADP and Pi and triggering the “power stroke, ‘’ in which the myosin head returns to its initial conformation, thereby sliding the actin filament toward the M line of the sarcomere .

Detailed explanation-2: -First, the action of the reaching myosin S1 head uses the energy released after the ATP molecule is broken into ADP and phosphate. Myosin binds actin in this extended conformation. Second, the release of the phosphate empowers the contraction of the myosin S1 region (Figure 4).

Detailed explanation-3: -After the power stroke, ADP is released; however, the cross-bridge formed is still in place, and actin and myosin are bound together. ATP can then attach to myosin, which allows the cross-bridge cycle to start again and further muscle contraction can occur (Figure 6.8).