genetic code, the information carried by DNA that determines the specific amino acids and their sequence in each protein synthesized by an organism. The code consists of the sequence of nucleotides in the DNA molecule of each chromosome in the nucleus of every cell. During transcription, a specific part of the code is transcribed into a sequence of nucleotides in the messenger RNA (mRNA). The mRNA travels from the nucleus to the cytoplasm, where it is translated into protein by the ribosomes. A codon consisting of three consecutive nucleotides in the mRNA codes for each amino acid in the protein. A change in the code may result in an incorrect sequence of the amino acids in the protein, causing a mutation. See also anticodon, transcription, translation.
