General & Nerve-Muscle Physiology · NEET PG Preparation Physiology
During excitation-contraction coupling in skeletal muscle, calcium ions are released from the sarcoplasmic reticulum into the sarcoplasm. Which speci…
Practice question from General & Nerve-Muscle Physiology (NEET PG Preparation Physiology), with the correct answer and a step-by-step solution.
easy · MCQ · Q-C18456
During excitation-contraction coupling in skeletal muscle, calcium ions are released from the sarcoplasmic reticulum into the sarcoplasm. Which specific protein do these calcium ions bind to in order to initiate contraction?
- A.Tropomyosin
- B.Troponin CCorrect answer
- C.Myosin light chain
- D.Alpha-actinin
Solution
Calcium ions bind to Troponin C (TnC) on the thin filament. This binding induces a conformational change that moves tropomyosin away from the myosin-binding sites on actin, allowing cross-bridge formation to occur.
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