What binds to troponin causing it to expose the binding site on actin to enable muscle cell contraction? A. Ca ++ (calcium) B. ACh (acetylcholine) C. PO 4 2− (phosphate) D. ADP (adenosine diphosphate)
Option A. Ca++ (calcium) binds to troponin causing it to expose the binding site on action to enable muscle cell contraction.
