Function of a ribosome

Function of a ribosome

Function of a ribosome

Ribosomes are complex organelles that make up most of a cell membrane and are composed of two types of particles, called ribosomal particles and ribosomal RNA. When the cell make proteins and RNA, the ribosomes catalyze the action by translating messenger RNA sequences into amino acids and transferring the amino acids to peptidyl transferase.Translation — the process of decoding the information in messenger RNA and forming continuous chains of amino acids to form proteins — is carried out by ribosomes.


Ribosomes consist of two subunits: one subunit (30S in bacteria and archaea, 40S in eukaryotes) decodes the mRNA, reading off the triplets of nucleotide that correspond to each amino acid; the other subunit (50S in bacteria and archaea, and 60S in eukaryotes) forms the peptide bonds.Yusupov, M. M. et al. Crystal structure of the ribosome at 5.5 Å resolution. Science 292, 883–896 (2001).A near atomic (0.55 nm) resolution map of an entire bacterial ribosome bound by messenger RNAs and transfer RNAs.

First detailed view of the intersubunit bridges. Nissen, P., Hansen, J., Ban, N., Moore, P. B. & Steitz, T. A. The structural basis of ribosome activity in peptide bond synthesis. Science 289, 920–930 (2000).The peptidyl-transferase centre is described as an RNA cage, with no proteins closer than 1.8 nm to the peptide bond to be synthesized. Peptide-bond formation is proposed to follow the rules of acid–base catalysis as described in serine proteases. The ribosome is described as a ribozyme. Also see references 35 and 36. (Source:www.nature.com)


Ribosomes are macro-molecular production units. They are composed of ribosomal proteins (riboproteins) and ribonucleic acids (ribonucleoproteins). The word ribosome is made from taking ‘ribo’ from ribonucleic acid and adding it to ‘soma’, the Latin word for body. Ribosomes can be bound by a membrane(s) but they are not membranous.Ribosomes are made of proteins and ribonucleic acid (abbreviated as RNA), in almost equal amounts. It comprises of two sections, known as subunits.

The tinier subunit is the place the mRNA binds and it decodes, whereas the bigger subunit is the place the amino acids are included.Prokaryotes have 30S subunit with a 16S RNA subunit and comprise of 1540 nucleotides bound to 21 proteins. The 50S subunit gets produced from a 5S RNA subunit that involves 120 nucleotides, a 23S RNA subunit that contains 2900 nucleotides and 31 proteins. (Source: www.microscopemaster.com)




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