ribosome, particle that is present in large numbers in all living cells and serves as the site of protein synthesis. Ribosomes occur both as free particles in prokaryotic and eukaryotic cells and as particles attached to the membranes of the endoplasmic reticulum in eukaryotic cells.
Ribosomes link amino acids together in the order specified by the codons of messenger RNA molecules to form polypeptide chains. Ribosomes consist of two major components: the small and large ribosomal subunits.
There are many ribosomes in each cell, each made up of two subunits. These two subunits lock around the messenger RNA and then travel along the length of the messenger RNA molecule reading each three-letter codon.
Ribosomes are tiny spheroidal dense particles (of 150 to 200 A0 diameters) that are primarily found in most prokaryotic and eukaryotic. They are sites of protein synthesis.
Ribosomes are cell structures present in large numbers in all living cells acting as the site of protein synthesis. In prokaryotes, they float freely in the cytoplasm, while in eukaryotes they are free or remain bound to the outer membrane of the endoplasmic reticulum.