Ribosome detail render

The ribosome is the cellular machinery responsible for protein synthesis, essential for all living beings. Learn about its structure and function.

About this subject

Ribosomes are molecular complexes found in all cells, responsible for translating messenger RNA into proteins. They consist of two subunits: the large and the small, which associate during protein synthesis. Each subunit contains ribosomal RNA (rRNA) molecules and specific proteins, forming a highly evolutionarily conserved structure.

The discovery of ribosomes is attributed to biologist George Palade in the 1950s, who observed them under electron microscopy, work that earned him the Nobel Prize in Medicine in 1974. In eukaryotic cells, ribosomes can be free in the cytosol or attached to the rough endoplasmic reticulum (RER), where they produce proteins destined for export or specific organelles. In prokaryotes, they are smaller (70S versus 80S) and located in the cytoplasm.

The function of ribosomes is central to life: they decode messenger RNA and catalyze the formation of peptide bonds between amino acids, generating polypeptide chains that fold into functional proteins. This process is targeted by various antibiotics, such as tetracycline and erythromycin, which selectively inhibit bacterial ribosomes. Mutations in human ribosomal proteins are associated with diseases like Diamond-Blackfan anemia and certain cancers.

Frequently Asked Questions

What are ribosomes?

Ribosomes are complexes of RNA and proteins that perform protein synthesis in cells, translating messenger RNA into polypeptide chains.

Where are ribosomes found in cells?

Ribosomes can be free in the cytosol or attached to the rough endoplasmic reticulum (RER). In prokaryotes, they are scattered in the cytoplasm.

What is the medical importance of ribosomes?

Ribosomes are targets of many antibiotics that block bacterial protein synthesis. Defects in human ribosomes are linked to diseases such as Diamond-Blackfan anemia and cancer.