What process occurs as myosin heads bind to actin?

The process that occurs as myosin heads bind to actin is known as cross-bridging. This is a fundamental mechanism in muscle contraction as myosin, a motor protein, forms temporary connections with actin filaments in the muscle fibers. When the myosin heads attach to actin, they pull on the actin filament, resulting in the sliding of the filaments past one another, which ultimately leads to muscle contraction.

Cross-bridge cycling is a critical part of the sliding filament theory of muscle contraction. It involves the binding of myosin to actin, followed by the power stroke, where the myosin head pivots and pulls the actin filament toward the center of the sarcomere. The process continues as long as ATP is available to detach and re-cock the myosin heads, allowing repeated cycles of cross-bridging.

Other options do not accurately represent the specific action of myosin binding to actin. Cell signaling refers to the communication processes that occur between cells, while myofibril contraction is a broader term that involves the entire muscle fiber's contraction mechanisms, including the role of cross-bridging. ATP synthesis, on the other hand, pertains to the production of ATP and is not directly related to the