There are 20 different amino acids, but there are more than 20 combinations of three nucleotide bases on DNA. There are 64 different combinations of three nucleotide bases on DNA, which is about 3 times more than the number of amino acids. Thus, the triplet code can produce 64 possible codon combinations. Different combinations of three nucleotide bases code for one amino acid are the reason why the DNA sequence is so different when the protein sequence isn’t.