Ribosome

Ribosome-a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
Function-They are complexes of proteins and three (prokaryotes) or four (eukaryotes) rRNA molecules called subunits. The main function of ribosomes is as the site of mRNA translation; once the two subunits are joined by the mRNA from the nucleus, the ribosome translates mRNA into a specific sequence of amino acids.