We'll see that the polypeptide as a whole has a great potential to form H bonds with other molecules as we'll see in the next lecture. Because these hydrogen bonds that are formed as a result of these atoms in the polypeptide basically creates the secondary structure of proteins as we'll see in the next lecture. So the polypeptide chain has the ability to form many hydrogen bonds and that's because each one of these amino acids basically contains two types of groups. It contains the NH group which acts as a hydrogen bond owner. And we have the Carbonal group Co that acts as the hydrogen bond acceptor. So what do we mean by that and why is that the case?