A codon is made up of 3 nucleotides.
Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base. Codons are crucial in the process of translation during protein synthesis, where each sequence of three nucleotides corresponds to a specific amino acid. This triplet nature of codons allows for the coding of 64 different combinations (4^3), which covers the 20 amino acids used in proteins.