Chapter 45, Problem 5TYU

Summary Introduction

To review:

The significance of the data on sarcomere structure in inspiring the sliding-filament model and the reason why the observation that muscle cells contain many mitochondria and endoplasmic reticulum is justified when the molecular mechanism of muscular contraction is understood.

Introduction:

The sliding-filament model of muscle contraction was proposed by Huxley and Hanson in 1954. The muscle fiber (cell) is made up of smaller units known as myofibrils. These are striated due to the presence of dark and light bands. A repeating unit between two Z lines is known as a sarcomere. The sarcomere shortens and lengthens as the muscles contract and relax, respectively.