Myosin-Actin Interaction Drives Muscle Motion Understanding the interaction between myosin and actin proteins reveals how mechanical motion is generated in muscles. Myosin II, an ATPase enzyme, reacts with ATP to produce energy necessary for movement. This process occurs outside muscle cells as well and serves as a foundation for understanding muscle function.
ATP Binding Triggers Mechanical Energy Release The binding of ATP to myosin causes it to detach from actin, initiating a series of steps that lead to mechanical movement. Upon hydrolysis of ATP into ADP and phosphate, energy is released which cocks the myosin head into a high-energy state ready for action.
Power Stroke: From Chemical Energy to Movement When phosphate releases from the cocked position of myosin during contraction, it generates force on actin—this power stroke results in actual muscle movement. The cycle continues with ADP release allowing another round of attachment along the filament chain; this illustrates how chemical energy transforms into mechanical work within our bodies.