Cardiac muscle contracts when _______ is available to bind with _______. A) Ca²⁺; tropomyosin B) Ca²⁺; myosin C) Ca²⁺; troponin D) Na⁺; troponin E) Na⁺; tropomyosin

Question

Quizplus · Accepted Answer

Cardiac muscle contraction is regulated by the binding of calcium ions (Ca2+) to troponin, which is a complex of three proteins (troponin C, troponin I, and troponin T) that is bound to tropomyosin. When calcium binds to troponin, it causes a conformational change in the troponin-tropomyosin complex, which allows myosin to bind to actin and initiate muscle contraction. Therefore, the correct answer is C, Ca2+ is available to bind with troponin.

Cardiac Muscle Contracts When _______ Is Available to Bind with _______

Cardiac Muscle Contracts When _ Is Available to Bind with _