Question

fill in the blank question
when ca²⁺ is released from the sarcoplasmic reticulum and binds to , it exposes the myosin binding sites on actin molecules.

Explanation:

In muscle contraction, calcium ions released from the sarcoplasmic reticulum bind to troponin. This binding causes a conformational change in the troponin - tropomyosin complex, which exposes the myosin - binding sites on actin molecules.

Answer:

troponin