Which molecule blocks the myosin head from binding to actin in a relaxed muscle?
A)tropomyosin
B)troponin
C)calcium
D)titin

Question

Quizplus · Accepted Answer

Tropomyosin is a protein that lies on the actin filament and covers the myosin binding sites in a relaxed muscle, preventing myosin from binding to actin. When calcium binds to troponin, it causes a conformational change in tropomyosin, exposing the myosin binding sites and allowing contraction to occur.

Which Molecule Blocks the Myosin Head from Binding to Actin