Question

practice it
lo 4.4. ______ ions bind the actin - myosin complex to start the muscle contraction process.
potassium
sodium
calcium
chlorine
magnesium

Explanation:

In muscle contraction, calcium ions play a crucial role. They bind to troponin - tropomyosin complex on the actin filaments, causing a conformational change that exposes the myosin - binding sites on actin, allowing the myosin heads to bind to actin and initiate the muscle contraction process.

Answer:

C. Calcium