Cytoskeleton | Microtubule, Microfilament, intermediate filament | Video 14

Описание: The cytoskeleton is a network of protein fiber inside the cell. The most obvious function of the cytoskeleton is to give mechanical support to the cell and maintain its shape. This is especially important for animal cells, which lack walls.
The eukaryotic cytoskeleton, which plays a major role in organizing the structures and activities of the cell, is composed of three types of molecular structures: microtubules, microfilaments, and intermediate filaments. there are three main types ( components) of fibers that make up the cytoskeleton:

Microtubules are the thickest of the three types; microfilaments (also called actin filaments) are the thinnest; and intermediate filaments are fibers with diameters in a middle range. All eukaryotic cells have microtubules, hollow rods constructed from a globular protein called tubulin. Microtubules shape and support the cell and also serve as tracks along which organelles equipped with motor proteins can move.

Microfilaments are thin solid rods. They are also called actin filaments because they are built from molecules of actin, a globular protein. Microfilaments are well known for their role in cell motility. Thousands of actin filaments and thicker filaments made of a protein called myosin interact to cause contraction of muscle cells. In the unicellular eukaryote Amoeba and some of our white blood cells, localized contractions brought about by actin and myosin are involved in the amoeboid (crawling) movement of the cells. The cell crawls along a surface by extending cellular extensions called pseudopodia (from the Greek pseudes, false, and pod, foot) and moving toward them. Intermediate filaments are named for their diameter, which is larger than the diameter of microfilaments but smaller than that of microtubules. Microtubules helps in maintenance of cell shape (tensionbearing elements), anchorage of nucleus and certain other organelles, formation of nuclear lamina.