It is an aqueous medium that does not have an apparent structure and properties. The cytosol, also called the cytoplasmic matrix or hyaloplasm, is located within the cells and constitutes the majority of the intracellular fluid of the cytoplasm, which is made up of cytosol and small organelles. The cytosol is separated by membranes, which form different compartments.
The cytosol constitutes a complex mixture of substances that are dissolved in water, this being its main component (approximately 85%). The other components are mainly ions, proteins, lipids, and carbohydrates gases carbon.
Two main types of granular structures are dispersed in the cytosol: ribosomes and glycogen granules, lipid globules, among others.
Ribosomes have a diameter of 20nm, some of them are free in the cytosol and are involved in the synthesis of proteins that are specific to the cell; others are associated with the cytoplasmic face of the endoplasmic reticulum, to synthesize proteins destined to be excreted or membrane proteins.
For their part, glycogen granules and lipid globules have a size and presence in highly variable numbers, although generally greater than that of ribosomes. These constitute fuel reserves.
The functioning of the cytosol varies according to the type of cell. In eukaryotic cells, the cytosol is located within the cell membrane. It is also included in the cytoplasm, the latter encompassing plastids, mitochondria and other organelles. In these cells, the cytosol does not encompass the structures of the organelles, nor does it encompass the internal fluids, it only represents a matrix liquid that is found around the organelles and although many metabolic pathways occur in it, others are contained within the organelles.
In contrast, in prokaryotic cells, most of the chemical reactions of metabolism take place within the cytosol, others occur in the periplasmic space or in the membranes. For this reason, representatives of all groups of biomolecules are found in the cytosol. In addition, cytoplasmic movements or currents (cyclosis) take place in the cytosol that lead to displacement of some organelles.
Although the cytosol has several functions, it acts mainly in the degradation of glucose (glycolysis) and is responsible for transmitting information through the plasma membrane of the cell, to the cell nucleus.
