Translation of mRNA. Colored transmission electron- micrograph (TEM) of ribosomes translating a messenger RNA (mRNA) strand for protein synthesis. Ribosomes (round, colored black) form a chain, seen here. Attached to them is a hair-like mRNA strand. mRNA is a molecule of ribonucleic acid which carries instructions to make proteins, as coded by a gene. Ribosomes move along the mRNA strand while reading these genetic instructions. Ribosomes are then responsible for making the protein which has been coded. A protein consists of a chain of amino acids arranged into a sequence and joined by peptide bonds. Magnification: unknown.