Answer:
power stroke
Step-by-step explanation:
- The process of muscle contraction requires several steps.
- The most famous theory on how the contraction and relaxation of muscles take place is the sliding filament theory.
- However, this theory has been refined and one important addition to it is the mechanism by which myosin can pull actin and cause shortening of the sarcomere.
- For the movement of myosin, it binds and releases actin and forms cross bridges.
- Myosin is subdivided into two regions - S1 and S2. The contraction of the S1 region is what constitutes the power stroke.
- An important requirement of the power stroke is the hydrolysis of ATP to release an inorganic phosphate which provides energy for the process.