cytosol


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 cells and makes up the majority of the intracellular fluid in 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, gases and carbohydrates.

Two main types of granular structures are scattered in the cytosol: ribosomes and glycogen granules, lipid globules, among others.

Ribosomes have a diameter of 20nm, some of them are found free in the cytosol and are involved in the synthesis of proteins that are characteristic of 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, the glycogen granules and the lipid globules have a very variable size and presence in number, although generally greater than that of the 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 the 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 fluid that is found around the organelles and although many metabolic pathways occur in it, others are contained within the organelles. .

On the other hand, 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, causing 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 cell’s plasma membrane to the cell nucleus.