The genetic code consists of the sequence of nitrogen bases in a polynucleotide chain of DNA or RNA. The bases are adenine (A), cytosine (C), guanine (G), and thymine (T) (or uracil, U, in RNA). The f...The genetic code consists of the sequence of nitrogen bases in a polynucleotide chain of DNA or RNA. The bases are adenine (A), cytosine (C), guanine (G), and thymine (T) (or uracil, U, in RNA). The four bases make up the “letters” of the genetic code. The letters are combined in groups of three to form code “words,” called codons. Each codon stands for (encodes) one amino acid, unless it codes for a start or stop signal. There are 20 common amino acids in proteins.
