Myosin-II cross-bridge: ATP-binding detaches, hydrolysis cocks head, actin-binding releases Pi → power stroke. Troponin-tropomyosin Ca²⁺-gated in striated muscle.
Myosin-II cross-bridge: ATP-binding detaches, hydrolysis cocks head, actin-binding releases Pi → power stroke. Troponin-tropomyosin Ca²⁺-gated in striated muscle.