Q. Calcium is important in skeletal muscle contraction because it
A) detaches the myosin head from the actin filament.
B) activates the myosin ATPase by binding to it.
C) binds to troponin to remove the masking of active sites on actin for myosin.
D) prevents the formation of bonds between the myosin cross bridges and the actin filament.
Explanation
[Solution] $Ca^{2+}$ binds troponin, shifting tropomyosin to expose myosin-binding sites on actin. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.