PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Voltage Gated Ion Channel
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Ligand Gated Ion Channel
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Troponin Protein
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Actin Protein
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Detailed explanation-1: -Bottom panel: Calcium (Ca2+) binds to troponin C, leading to a conformational change which moves the tropomyosin molecule and makes the myosin binding site accessible to the myosin head. The other troponins also contribute to this process.
Detailed explanation-2: -Regulation of Troponin and Tropomyosin If present, calcium ions bind to troponin, causing conformational changes in troponin that allow tropomyosin to move away from the myosin-binding sites on actin.
Detailed explanation-3: -Upon binding calcium, troponin moves tropomyosin away from the myosin-binding sites on actin (bottom), effectively unblocking it.
Detailed explanation-4: -Troponin plays a central role in the calcium-regulation of muscle contraction: Troponin is the sole calcium-binding component of thin filaments (actin-tropomyosin-troponin complex) of striated muscles.
Detailed explanation-5: -If present, calcium ions bind to troponin, causing conformational changes in troponin that allow tropomyosin to move away from the myosin binding sites on actin.