Power stroke

Definition

The power stroke is a phase during muscle contraction where the myosin head pulls the actin filament towards the center of the sarcomere, resulting in muscle shortening. This process is fueled by ATP hydrolysis, converting chemical energy into mechanical work.

Related terms

Sarcomere:

The functional unit of a muscle fiber, composed of long strands of proteins (actin and myosin) that slide past each other to create contraction.

Myosin:

A motor protein that interacts with actin in muscle cells to produce contraction, using ATP as an energy source.

Actin:

A globular protein that forms filaments which slide past myosin molecules during muscle contraction, playing a key role in cell movement and structure