2. Genetic code and ribosomes

2.3 Ribosomes

2.3.1 Structure

a. General features

Ribosomes are ribonucleoprotein complexes (i.e. composed of proteins and RNA) present in eucaryotic and procaryotic cells.

Their function is to synthesize proteins by decoding the information contained in the messenger RNA. They are made up of:

  • Ribosomal RNA, mediating catalytic functions (3–4 rRNAs, one copy of each).

  • Ribosomal proteins (50 to 80 different proteins, one copy of each).

There are millions of ribosomes in each cell.

They are generated from the assembly of a large subunit and a small subunit (figure 14).