genetic code

specific information, carried by DNA molecules, that controls the particular AMINO ACIDS and their positions in every PROTEIN and thus all the proteins synthesized within a cell. Because there are just four nucleotides, a unit of three bases becomes the smallest unit that can produce codes for all 20 amino acids. The transfer of information from gene to protein is based upon three consecutive nucleotides called codons. A change in the genetic code results in an amino acid being inserted incorrectly in a protein, resulting in a MUTATION .