Why are calcium ions necessary for skeletal muscle contraction?
A) Calcium ions increase the speed of the action potential transmitted along the sarcolemma.
B) Calcium ions release the inhibition on Z discs.
C) Calcium ions trigger the binding of myosin heads to actin filaments.
D) Calcium ions cause ATP binding to actin.
E) Calcium ions bind to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments.

Question

Quizplus · Accepted Answer

Calcium ions trigger the binding of myosin heads to actin filaments, allowing for the actual contraction of the muscle to occur. Without calcium ions, the myosin heads cannot bind to actin and muscle contraction cannot occur.

Why Are Calcium Ions Necessary for Skeletal Muscle Contraction