Muscle contraction is triggered A)in response to an increase in the cytoplasmic Ca²⁺ concentration. B)in response to a decrease in the cytoplasmic Ca²⁺ concentration. C)in response to an increase in the cytoplasmic cAMP concentration. D)in response to a decrease in the cytoplasmic cAMP concentration. E)in response to an increase in the cytoplasmic titin concentration.

Question

Quizplus · Accepted Answer

Muscle contraction is triggered by an increase in the cytoplasmic Ca2+ concentration. This increase in Ca2+ concentration leads to the binding of Ca2+ to troponin, which causes a conformational change in tropomyosin, uncovering the myosin-binding sites on actin, allowing myosin heads to bind and initiate the contraction process.

Muscle Contraction Is Triggered