| a codon that stops the synthesis of a protein molecule. |
| chain termination codon n. See stop codon. |
| stop codon n. Any of three codons, UAA, UAG, or UGA, that signal the termination of the synthesis of a protein. Also called chain termination codon. |
| stop codon (stŏp) Pronunciation Key
Any of three codons in a molecule of messenger RNA that do not code for an amino acid and thereby signal the termination of the synthesis of a protein. The three stop codons are UAA, UAG, and UGA, where U is uracil, A is adenine, and G is guanine. Also called termination codon. |