Calcium plays what role in skeletal muscle contraction?
a. Binds the myosin head, opening up cross-bridge formation
sites on actin
b. Binds tropomyosin, causing a conformational change that moves
troponin, unblocking the crossbridge formation site on the
actin
c. Binds globular actin, rolling the tropomyosin from its
position, and unblocking the cross-bridge binding site on
troponin
d. Binds troponin, causing a conformational change that moves
tropomyosin, opening up the cross-bridge formation site on the
actin molecules