And we'll see why that's important in just a moment. And by reacting that same amino acid with Tbock, we're essentially adding this entire component onto the nitrogen and that blocks and deactivates this nitrogen. What that means is this nitrogen no longer forms peptide bonds, but this carbon becomes much more likely to form peptide bonds and that will become important in just a moment. So once we prepare our amino acids, let's go to step number two. In step number two, we actually want to take that first amino acid in line from the terminal carboxyla and attach it onto that solid surface. So in step two, an amino acid that has been protected as the amino group by Tbock is attached onto a solid surface.