Now, once we form them, it's the hydrogen bonds that exist between the NH group of one amino acid and the co group of another amino acid that stabilizes these structures and allows them to exist for an extended period of time. Now, let's focus on this amino acid here. So we see that we have this NH group of this amino acid here that interacts with the co group of this amino acid here. The question is, what is the numerical relationship between this group here and this group here? So let's count. So we have this peptide bond here.