Codon

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Codon \Co"don\ (k[=o]"d[o^]n), n. (Molecular biology)
     a sequence of three nucleotides in a genome or a DNA or
     messenger RNA molecule, which specifies the incorporation of
     one amino acid or is a stop signal, during the biosynthesis
     of proteins. Codons occur within the protein-coding segments
     of the DNA or RNA genome of living organisms. The amino acid


     sequence of proteins synthesized on ribosomes is thus
     determined by the sequence of the nucleotides in the genome.
     [PJC]
  
     Note: Outside of coding regions, there is no direct
           correspondence of the nucleotide sequence with protein
           sequence, and certain signalling functions of nucleic
           acids are not specified by three-nucleotide codons.
           Certain types of polypeptide synthesized in living
           organisms are not synthesized on ribosomes, and the
           sequences of these polypeptides do not have a
           corresponding nucleotide sequence in the genome.
           [PJC]

From WordNet (r) 2.0 [wn]:

  codon
       n : a specific sequence of three adjacent bases on a strand of
           DNA or RNA that provides genetic code information for a
           particular amino acid