Activation of myosin?

[Vangeek]

Could anyone help me to describe the activation of myosin? Is it when ATPase in the myosin head hydrolyzes ATP to ADP and P which provides energy needed to return myosin head to its prestroke high-energy? Or it is when ATP attaches to myosin head and detach the cross bridge? Please help!!!!

[MrMistery]

it's kind of a weird question, but I would guess that if I had to pick I would say the ATP-bound state is the activated state..

[Vangeek]

Complete question was this: Every muscle contraction involved the interaction of myosin and actin filaments. This interaction can occur only after myosin has been activated. Describe the activation of myosin. ??? I guess, without both, ATP-bound state that detaches myosin head, or later ATP hydrolysis that sets myosin head into high-energy config for subsequent cross-bridge, interaction between myosin and actin would not be possible??