PHYSIOLOGY
MUSCLE CONTRACTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Na+
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K+
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Ca2+
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Fe2+
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Detailed explanation-1: -Reason: Calcium ions bind troponin causing the displacement of tropomyosin, allowing the myosin head to bind actin.
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: -(1) Calcium binds to troponin C, causing the conformational shift in tropomyosin that reveals myosin-binding sites on actin.
Detailed explanation-4: -The calcium ions released from endoplasmic reticulum72) bind to the calcium-binding subunit of troponin (troponin-C (TnC), ∼18 kDa), and the inhibition by troponin is neutralized to trigger muscle contraction.