How does the release of calcium ions regulate muscle contraction?

Tropomyosin is a protein that covers the actin binding site. This prevents a cross-bridge forming between the myosin and actin filaments whilst the muscle is at rest. Calcium ions bind to troponin molecules, changing their shape. This change in the troponin moves the tropomyosin away from the actin binding site enabling the myosin head to attach. When the muscle relaxes, calcium ions are removed and the tropomyosin returns to its original position.

ET
Answered by Emily T. Biology tutor

4661 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain how changes in temperature and pH affect the rate of an enzyme-catalysed reaction. Give appropriate diagrams to illustrate your answer. [6]


What is the difference between mitosis and meiosis


Describe the role of RuBISCO in photosynthesis.


Describe the differences in structure between an artery and a vein.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning