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A description of sarcomeres and skeletal muscle contraction

What is a sarcomere?

What are some functional differences between skeletal and cardiac muscles?

What happens within the muscle fibers to cause a muscle to contract?

Solution Preview

A sarcomere is the functional unit of a muscle cell; it is the smallest part of a muscle cell with the ability to contract.
<br>It is made up of two halves of an I-band, an A-band and has z-disks on either end. If you're not familiar with the terminology, let me explain more clearly:
<br>A muscle is powered by myosin, a motor molecule. It uses energy from ATP to move along a structural protein called actin. The A-band is composed of myosin fibres, with the direction of pull towards the centre. The I band consists of actin filaments, which is what the myosin pulls against. The actin filaments are anchored in the z-disks, so that when ...

Solution Summary

A description of sarcomers and the function of muscle fibers to cause contraction. Includes a figure from Lodish et al, Molecular Cell Biology 3e, 1996. Also includes a brief description of the differences between skeletal and cardiac muscle.