And so in step four, the activated amino acid that is also blocked by that Tbox. So the molecule we form in step number one is then mixed with amino acid attached onto that solid surface that we form in step three. And this forms a peptide bond. So in this diagram, we take this molecule here and we mix it with this amino acid attached onto our solid surface as shown. And we form a peptide bond between this carbon here. So this carbon right over here and this nitrogen right over here.