Contraction of a muscle cell requires the influx of calcium into the sarcoplasm.

Question

Quizplus · Accepted Answer

Calcium is necessary for the binding of myosin and actin, which initiates muscle contraction. Calcium ions are released from the sarcoplasmic reticulum in response to nerve impulses and they bind to troponin, which moves tropomyosin aside to expose the binding sites on actin for myosin to bind to. Without calcium, muscle contraction cannot occur.

Contraction of a Muscle Cell Requires the Influx of Calcium