International Union of Pure and Applied Chemistry - Amino Acid and Nucleotide Base Codes

Amino Acid and Nucleotide Base Codes

IUPAC also has a system for giving codes to identify amino acids and nucleotide bases. IUPAC needed a coding system that represented long sequences of amino acids. This would allow for these sequences to be compared to try to find homologies. These codes can consist of either a one letter code or a three letter code. For example:

• Alanine: Single letter code: A, Three letter code: Ala

These codes make it easier and shorter to write down the amino acid sequences that make up proteins. The nucleotide bases are made up of purines (adenine and guanine) and pyrimidines (cytosine and thymine). These nucleotide bases make up DNA and RNA. These nucleotide base codes make the genome of an organism much smaller and easier to read.