PHYSIOLOGY
MUSCLE CONTRACTION
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Troponin
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Nebulin
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Titin
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Tropomyosin
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Detailed explanation-1: -Tropomyosin blocks myosin binding sites on actin molecules, preventing cross-bridge formation, which prevents contraction in a muscle without nervous input. The protein complex troponin binds to tropomyosin, helping to position it on the actin molecule.
Detailed explanation-2: -1 Tropomyosin. TM regulates smooth muscle contraction by blocking the myosin binding sites on actin, preventing actin–myosin interaction.
Detailed explanation-3: -1 -tropomyosin, when interacting with D292V actin, can completely block binding interactions and motility of myosin II, albeit in a mutant filament.
Detailed explanation-4: -Two other components of the thin filament are tropomyosin and troponin. Actin has binding sites for myosin attachment, but strands of tropomyosin block the binding sites and prevent actin-myosin interactions when the muscles are at rest. Tropomyosin is regulated by troponin, which is regulated by calcium (Ca2+) ions.
Detailed explanation-5: -Tropomyosin hinders the cross-bridge formation and contraction of muscle without nervous input thereby blocking myosin binding sites on actin molecules. Troponin binds to tropomyosin and helps to position it on the actin molecule.