The energy for cross bridge cycling during muscle contraction is provided by.. ATP or Ca2+? HELP! NEED ASAP!?

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  • Anonymous
    1 decade ago
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    ATP.

    ATP binds to myosin and then, in the presence of Ca++, troponin, and tropomyosin, a myosin binding site is exposed on the thin filament and a physical link is formed between actin and myosin. The ATPase activity of the myosin is then exerted, cleaving a phosphate bond of the ATP, releasing energy, and causing the myosin head to swivel.

  • 4 years ago

    The muscle cells will consistently make the main of ATP in uncomplicated cellular applications whether or no longer they are contracting or relaxing. interior the flow-bridge cylcing, the ATPase myosin heads launch from actin while the ADP and Pi from ATP hydrolysis are released and the myosin heads take a sparkling ATP. that's rest for a quick peroid of time, if the ATP is in no way hydrolyze and the myosin filaments do no longer slide alongside the actin filaments, yet complete rest interior the sense we frequently use it in would not take place until the cytosolic Ca2+ concentration turns into low sufficient the place troponin would not bind to tropomyosin, which then blocks the actin-myosin binding web content.

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