Codon

Definition

Codon in plain English

Your DNA is an instruction manual for building proteins, and a codon is one three-letter "word" in that manual. The letters are chemical units called nucleotides (A, U, G, C), and every group of three spells out one amino acid — the beads that string together to make a protein. There are 4 × 4 × 4 = 64 possible three-letter words: 61 name an amino acid, and 3 are "stop" signs that tell the cell the protein is finished. Think of it like reading a recipe three letters at a time, where each little word says "add this ingredient" and a few say "you're done."

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