Now, the variable section of our polypeptide are these groups, the side chain groups of our amino acid. So we have sidechain R one, side chain R two, side chain R three, and so forth. Now, if we study every single amino acid in our polypeptide. 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.