Genes must be expressed in precise levels and at the exact moment if the complex balance regulating cell activity is to be maintained. Messenger RNA (mRNA) conveys genetic information from DNA to ribosomes, where proteins are synthesised through the union of amino acids. These amino acids are supplied by fragments of transfer RNA (tRNA), which decode the information contained within the mRNA codons (group of three bases sequencing each amino acid) in order to chain them correctly and synthesise each protein.