And it turns out that cells use triplet nucleotide sequences known as codons to encode for that amino acid. Because if we multiply four times four times four in our triplet, that would give us a value greater than 20. It would give us 64. Now we'll see why that's important in just a moment when we discuss fact number four. So for example, the nucleotide SequenceL uracil, uracil. This corresponds to the specific amino acid phenylalanine, while UUG corresponds to the specific amino acid leucine.