Question

multiple choice question
during excitation - contraction coupling, calcium binds to
myosin
actin
troponin
tropomyosin
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Explanation:

During excitation - contraction coupling in muscle cells, calcium ions bind to troponin. This binding causes a conformational change in troponin which then moves tropomyosin away from the myosin - binding sites on actin, allowing myosin to bind to actin and initiate muscle contraction.

Answer:

C. troponin