What are ribosomes?

Ribosomes are small, complex molecular machines that are found within cells. They are composed of ribosomal RNA (rRNA) and proteins, and they play a central role in the process of protein synthesis, or translation. Translation is the process by which the information contained in the genetic code of DNA is used to synthesise proteins.

During translation, ribosomes bind to messenger RNA (mRNA) molecules, which are produced from DNA and contain the genetic code for a specific protein. The ribosome reads the mRNA code, one codon (a sequence of three nucleotides) at a time, and uses this information to synthesise a chain of amino acids. This process is known as translation.

Ribosomes are made up of two subunits, the small subunit and the large subunit. The small subunit is responsible for recognizing the mRNA and binding to it, while the large subunit is responsible for synthesising the protein. The small subunit also contains a site called the A site, where the aminoacyl-tRNA (a molecule that carries an amino acid) binds. The large subunit contains a site called the P site, where the growing polypeptide chain is attached.

Ribosomes are found in many different types of cells, including prokaryotes (bacteria) and eukaryotes (plants, animals, and fungi). In eukaryotes, ribosomes can be found in the cytoplasm, as well as in the endoplasmic reticulum (ER) and the Golgi apparatus. Ribosomes found in the ER are involved in the synthesis of proteins that will be secreted or used within the cell, while ribosomes found in the Golgi apparatus are involved in the modification, sorting, and transport of proteins.

Ribosomes are important for many different cellular processes, including the synthesis of enzymes, hormones, and other proteins that are essential for the proper functioning of cells. Dysfunction or defects in ribosomes can lead to a number of diseases and disorders, including cancer and neurodegenerative disorders.