Explain the sliding filament model of muscular contraction

The presence of calcium ions causes tropnonin to detach from tropomyosin-this exposes the mysoin head binding sites. Myosin head groups attach to the surrounding actin filaments forming a cross bridge. The head group then bends, allowing the myosin (thin filament) to be pulled along along and so overlap more with the  action (thick filament). This is the power stroke. ADP and Pi are released. The cross bridge is broken as new ATP attaches to the myosin head. The head group moves backwards as ATP is hydrolysed to ADP and Pi. This occurs as energy is required for the myosin heads to return to its original state. It can then form a cross bridge with the actin and bend again.

KD
Answered by Karishma D. Biology tutor

6692 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain the importance of accessory pigments in photosynthesis.


Describe and explain the mechanism behind the specificity of enzyme reactions.


Describe the events that occur leading to an action potential, and briefly explain why it is described as "all or nothing"?


Explain the process of phagocytosis


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences