Chapter 45, Problem 3CQ

Summary Introduction

To determine: The role of energy with regard to the mechanism by which skeletal muscle cells contract.

Introduction:

Actin and myosin interact to promote muscle contraction and shortening. Myosin proteins associate in a parallel way with the extension of hinges and heads on the sides to form cross-bridges.

 Cross-bridge cycle during muscle contraction involves the following sequence of events:

• Binding of a cross-bridge to a thin filament.
• Movement of cross-bridge towards the H zone of the sarcomere.
• Detachment of the cross-bridge from the actin filament.
• Movement of cross-bridge away from the H zone for the cycle to begin again.