The cytoskeleton: what it is, structure, function and where it is found. Here’s everything explained in this biology summary.
The cytoskeleton is a dynamic three-dimensional structure (muscular and skeletal) that fills the cytoplasm and allows both movement and stability of the human organism. Its fibers, rather long (microfilaments, microtubules and intermediate filaments), are among other things polymers of subunits.
Unlike the skeleton , the cytoskeleton is very dynamic as it can lengthen or shorten quite quickly and allows cells to change shape.
Finally, in most humans and animals, a “critical” concentration is increasingly common, that is, a high concentration of the aforementioned subunits that favors the construction of the filaments while allowing deconstruction, a property that allows the cell to quickly verify the structure of the cytoskeleton.
The network of microfilaments
Microfilaments are a network with a diameter of six nanometers (6 nm) that are important for the anchoring of plasma membrane proteins and serve to produce cell movement.
The basilar filament is formed, instead, by a protein called actin that has a weight of forty-two kilodaltons (42 KD) and forms thin filaments inside the muscle. However, it is important to underline that inside the aforementioned actin cells, there are the monomeric protein called G-actin (for globular actin) and the “6 nm” filament called F-actin (for filamentous actin).
Microfilament fibers
In most cells the ends of the filaments are oriented towards the edge and in the cytoskeleton they exist in maximum concentration, and in association with the cell periphery where they play a relevant role in the anchoring of proteins in the membrane.
Microfilaments can also be organized into bundles (stress fibers) that serve as contractile elements. The latter are important because they allow to maintain the connections between the tissue and the surface on which it develops, and could be important for generating the directional force during cell motility.
These just described represent only some of the characteristics of the microfilaments of a cytoskeleton.
The functions of actin
The functions of actin are associated to change the properties of the network of the aforementioned microfilaments in cells and in this regard it should be added that there are also proteins, such as “filament microfilaments” that bind together to produce bundles of actin itself.
Cells can also control the length of the filaments with the action of proteins, and produce two short ones that have the purpose of maintaining them at a certain length. This condition causes the cells to produce the “capping” protein that in turn is able to prevent the addition of new actin subunits.
The contraction of cells
In the human body, the high contraction of muscle cells is due to a series of biochemical phenomena closely related to the cytoskeleton system. Finally, the cytoskeleton also favors the transport of some vesicles containing numerous neurotransmitters that intercede on the cells completing the process of the nervous system .