Atlas of Plant and Animal Histology
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7. CYTOSOL

« Lipid drops Cytoskeleton »

Cytosol is the hydrated milieu that surrounds organelles and nucleus

Cytosol contains many types of molecules and ions, so concentrated that it is a gel-like substance.

Cytosol is the cytoplasm excluding organelles and nucleus, and cytoplasm is cytosol plus organelles, but not the nucleus. Cytosol is a very concentrated aqueous solution around organelles and nucleus that can be up to more than half of the cell volume of the animal cells, whereas in the mature plant cells most of the cellular volume is occupied by a large vacuole.

Cytosol is mostly constituted by water containing a large amount of organic molecules and ions. The concentration of molecules and ions can be so high that makes cytosol a viscous gel-like solution. Unlike the extracellular space, cytosol has a higher concentration of potassium and a lower concentration of sodium and calcium. It is a buffered solution with pH 7 to 7,4.

An intense molecular activity takes place in the cytosol: many metabolic reactions like glycolysis, translation of mRNA to proteins by free ribosomes, signaling cascades for cell communication and for communication between cellular compartments, etcetera. Ions, second messengers, and larger molecules diffuse through the cytosol. Vesicles also move through cytosol from the source compartment toward the target compartment.

Cytoskeleton is also located in the cytosol. Cytoskeleton is a set of proteins organized as filaments that work as the skeleton of the cell, as well as the muscles of the cell. These filaments are really malleable to accomplish the cell needs. In the cytosol, there are also stores of lipids as lipid drops, and carbohydrates as glycogen.



« Lipid drops Cytoskeleton »

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Actualizado: 24-09-2016. 10:59