The five steps listed below are involved in excitation-contraction coupling.
1) A wave of depolarization passes through the T-tubules.
2) Ca²⁺ binds to and causes a conformational change in troponin.
3) Tropomyosin moves to expose myosin-binding sites on the actin.
4) Ca²⁺ is released from the sarcoplasmic reticulum.
"5) Cross-bridges form and produce a contraction.
Which of the following lists the steps in the CORRECT order of events?"

Question

Quizplus · Accepted Answer

The correct sequence for excitation-contraction coupling starts with the depolarization of T-tubules (1), followed by the release of calcium ions from the sarcoplasmic reticulum (4). Calcium then binds to troponin, causing a conformational change (2), which leads to the movement of tropomyosin and the exposure of myosin-binding sites on actin (3). Finally, cross-bridges form between actin and myosin, resulting in muscle contraction (5).

The Five Steps Listed Below Are Involved in Excitation-Contraction Coupling