PHYSIOLOGY
SLIDING FILAMENT MODEL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Na+ and K+
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Ca2+ and ATP
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Ca2+ and Na+
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Ach and K+
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Detailed explanation-1: -The energy released during ATP hydrolysis changes the angle of the myosin head into a cocked position. The myosin head is then in a position for further movement possessing potential energy. The enzyme myosin ATPase catalyses the reaction in the presence of Ca2+ and Mg2+. So, the correct answer is ‘Myosin’.
Detailed explanation-2: -Answer and Explanation: Calcium is required for cross-bridge formation process of muscle contraction. Whereas, the ATP is required to detach the myosin head from the actin-binding site for the next contraction cycle to begin. The tropomyosin molecules block the myosin-binding site on the actin filament.
Detailed explanation-3: -Ca2+ ions play an important role in muscle contraction by creating interactions between the proteins, myosin and actin. The Ca2+ ions bind to the C component of the actin filament, which exposes the binding site for the myosin head to bind to in order to stimulate a muscle contraction.