Proteins

The table above shows the genetic code - how the DNA code is converted into amino acids. Proteins (polypeptides) are made up of amino acids (coded for by a sequence of three base pairs in the DNA). Although there are 4 x 4 x 4 (64) different combinations of four base pairs (G, T, A and C) there are only twenty different amino acids. This is because some triplet codons code for the same amino acid and some triplet codons are STOP and START codes. For example, AAA and AAG both code for the amino acid phenylalanine (//phe//) and TAA and TAG both code for STOP in the protein chain. media type="custom" key="26975308"media type="custom" key="26975310"