PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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myosin
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troponin
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tropomyosin
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actin
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Detailed explanation-1: -A model of thin filament was generated by adding tropomyosin and troponin. During the process to provide the structural evidence for the model, the troponin arm was found to protrude from the calcium-depleted troponin and binds to the carboxyl-terminal region of actin.
Detailed explanation-2: -When calcium binds to troponin, the troponin changes shape, removing tropomyosin from the binding sites. The sarcoplasmic reticulum stores calcium ions, which it releases when a muscle cell is stimulated; the calcium ions then enable the cross-bridge muscle contraction cycle.
Detailed explanation-3: -Troponin interacts with tropomyosin. When stimulated by calcium, troponin undergoes a conformational change that moves the tropomyosin and exposes the myosin binding sites on the actin protein.