Q. Arrange the given steps of muscle contraction in the series of events from first to last I. Myosin head binds to the exposed active site on action to form a cross bridge II. The Z-line attached to these actin are also pulled in wards there by causing shortening of sarcomere also called contraction III. This pulls the attached actin filaments towards the centre of A -band The correct option is
A) I $\rightarrow$ II $\rightarrow$ III
B) III $\rightarrow$ II $\rightarrow$ I
C) I $\rightarrow$ III $\rightarrow$ II
D) III $\rightarrow$ I $\rightarrow$ II
Explanation
By utilizing the energy from ATP hydrolysis, the myosin head binds to the exposed active sites on actin to form a cross bridge. This pulls the attached actin filaments towards the centre of A-band. The Z-line attached to these actin are also pulled inwards thereby causing the shortening of sarcomere, i.e., contraction
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.