PHYSIOLOGY
MUSCLE STRUCTURE FUNCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Myosin head detaches from actin
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Myosin head forms cross-bridge
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Myosin undergoes power stroke
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Myosin releases calcium
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Detailed explanation-1: -Further, this detached myosin filament head hydrolyses ATP, and restores its starting position. Hence, the correct answer is (B) ‘When ATP attaches to myosin head’. Note: The binding of ATP results in the release of actin, in this way it allows actin and myosin to become detached from each other.
Detailed explanation-2: -ATP then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site. ATP can then attach to myosin, which allows the cross-bridge cycle to start again; further muscle contraction can occur.
Detailed explanation-3: -The motion of muscle shortening occurs as myosin heads bind to actin and pull the actin inwards. This action requires energy, which is provided by ATP. Myosin binds to actin at a binding site on the globular actin protein.