Calcium is important in skeletal muscle contraction because it :-
Calcium is important in skeletal muscle contraction because it :-
(1) binds to troponin to remove the masking of active sites on actin for myosin.
(2) activates the myosin ATPase by binding to it.
(3) detaches the myosin head from the actin filament.
(4) prevents the formation of bonds between the myosin cross bridges and the actin filament.
2 Answers
(1) binds to troponin to remove the masking of active sites on actin for myosin.
"But troponin-C combines with Ca++ ion, some Physiochemical changes occur in Troponyosin & Tropomyosin move away from active site of actin".
Correct option (1) binds to troponin to remove the masking of active sites on actin for myosin.
Explanation
Calcium plays a key regulatory role in muscle contraction. Ca2+ ions bind to troponin and changes its shape and position. This in turn, alter the shape and position of tropomyosin and hence, the active sites on F-actin are exposed. Due to this, myosin cross-bridges are able to bind to these active sites and muscle contraction occurs.