A polyribosome (or polysome or ergasome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”.[1] It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides. Originally coined "ergosomes" in 1963, they were further characterized by Jonathan Warner, Paul M. Knopf,[2] and Alex Rich.