Excitation Contraction Coupling I

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.