| DNA Codon | mRNA Codon | Amino Acid | 1-Letter | 3-Letter | Type |
|---|
How to Use the Genetic Code Table
Search: Type any DNA codon (e.g. ATG), mRNA codon (e.g. AUG), amino acid name (e.g. Methionine), one-letter code (e.g. M), or three-letter abbreviation (e.g. Met). The table filters instantly.
Filter buttons: Use the filter buttons to show only start codons, stop codons, or all standard coding codons. Click "All 64" to reset the view.
Codon format: DNA codons are shown 5'→3' using T (thymine). The mRNA column replaces T with U (uracil) as it appears during translation.
About the Standard Genetic Code
The standard genetic code defines how three-nucleotide codons in mRNA are read by ribosomes and translated into amino acids during protein synthesis. It is nearly universal across all living organisms.
Total codons: 64 (4³ = 4 × 4 × 4)
Amino acids coded: 20 standard amino acids
Start codon: AUG → Methionine (Met / M)
Stop codons: UAA (Ochre), UAG (Amber), UGA (Opal)
Coding codons: 61 (64 − 3 stop codons)
// Code is degenerate — most amino acids have
// more than one codon (synonymous codons)
Degeneracy of the Genetic Code
The genetic code is degenerate because multiple codons can encode the same amino acid. For example, Leucine is encoded by 6 codons (UUA, UUG, CUU, CUC, CUA, CUG). Changes at the wobble (third) position of a codon often produce the same amino acid, buffering against point mutation effects.
Start and Stop Codons
AUG is the universal start codon and also codes for Methionine anywhere in a protein. The three stop codons — UAA (Ochre), UAG (Amber), and UGA (Opal) — do not encode any amino acid; they signal the ribosome to terminate translation and release the polypeptide chain.