biology

Ribosomes

Ribosomes are small particles, composed of RNA and proteins. Present in all the cells where protein synthesis takes place, they are composed of two subunits, one of which is slightly larger than the other, for which the presence of magnesium is necessary for adhesion. They have an analogous structure in prokaryotes and eukaryotes, but differing in mass, which is smaller in the former.

The function of ribosomes is of fundamental importance for protein synthesis.

In cells that synthesize "export" proteins, such as digestive enzymes that are secreted in the stomach or intestines, most ribosomes adhere to the endoplasmic reticulum membranes. The endoplasmic reticulum covered by ribosomes is called the rough endoplasmic reticulum. In cells with a rough endoplasmic reticulum, the network of membranes represents a pathway through which the substances entering or leaving the cell are channeled.

A certain number of ribosomes bound to a long molecule of messenger RNA constitutes, as a whole, a "polyribosome" or "polysome".

Click on the names of the various organelles to read the in-depth analysis

Image taken from www.progettogea.com

Edited by: Lorenzo Boscariol