A set of three adjacent nucleotides, also called triplet, in mRNA that base-pair with the corresponding aniticodon of tRNA molecule that carries a particular amino acid, hence, specifying the type and sequence of amino acids for protein synthesis.
GCC (Guanine–Cytocine-Cytocine) → alanine
GUU (Guanine-Uracil-Uracil) → valine
CUA (Cytosine-Uracil-Adenine) → leucine
UCA (Uracil-Cytosine-Adenine) → serine
Related terms: ambiguous codon, start codon, stop codon.
Synonym: coding triplet.