ANATOMY

Detailed explanation-1: -ATP binding causes myosin to release actin, allowing actin and myosin to detach from each other. After this happens, the newly bound ATP is converted to ADP and inorganic phosphate, Pi.

Detailed explanation-2: -Relaxation: Relaxation occurs when stimulation of the nerve stops. Calcium is then pumped back into the sarcoplasmic reticulum breaking the link between actin and myosin. Actin and myosin return to their unbound state causing the muscle to relax.

Detailed explanation-3: -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-4: -ATP is also used to lower myoplasmic calcium levels during muscle relaxation. Thus, muscle contractility is intimately linked to the proper control of sarcomeric Ca2+ delivery and (or) removal and ATP generation and (or) utilization.

Detailed explanation-5: -ATP is required for both muscle contraction and muscle relaxation.