Following transcription and splicing, mature mRNA travels to the ribosome and displays the start codon. A tRNA molecule which has an anti codon that is complementary to the mRNA start codon matches with the mRNA molecule. The tRNA molecule has an amino acid attached to it. Next, another tRNA molecule comes to the ribosome to match to the next codon on mRNA. A peptide bond forms between the amino acid molecules on the tRNA molecules. Once this has occurred, the previous tRNA molecule is released to be reused. This process continues until a stop codon is reached on the mRNA. A complementary tRNA molecule matches and this has no amino acid attached to it. The previous amino tRNA is released and the polypeptide chain is also released which folds and forms bonds to produce the secondary, tertiary and for some, the quaternary structures