So every single Carbonal group in our amino acid is a hydrogen bond acceptor. And every one of these and age groups is basically our hydrogen bond donor. And that will become important in our discussion of the secondary structure of proteins. Now previously we discussed how these peptide bonds, these green bonds are actually formed. Now let's discuss what the nature of these peptide bonds is. So in other words, are these peptide bonds single bonds as shown in the following diagram or are they something else?