We simply modify this last nucleotide in the codon sequence and we form GAC. And we know from the genetic code that GAC codes for aspartate, which is the amino acid that we want to build in the first place. And notice that because C will not pair up with tea, no hydrogen bonds are actually formed between these two nucleotides. But that's okay, because this will still hybridize. It will still anneale because all the other bases are paired up correctly. So as long as we use the exact temperature conditions needed for annealing to take place.