Codons are three-letter codes that make up the genetic code. Both RNA and DNA have triplets known as codons. Each codon codes one of 20 amino acids that the body uses to synthesize amino acids.
In the DNA genetic code, most amino acids can be coded for by more than one codon. This allows the same amino acids to be included in DNA and protein synthesis. The DNA codons utilize the nucleotides thymine, guanine, adenosine and cytosine. The RNA codons utilize uracil instead of thymine. DNA codons are read in the 5’ to 3’ direction, and RNA codons are read in the 3’ to 5’ direction.