So what exactly is an alpha helix? Well, an alpha helix is formed when we have our polypeptide chain and that polypeptide chain begins to twist to form a rodlike structure. And inside that rod like structure, we have the backbone. And on the outside we have those R chain groups that are pointing outside of that alpha helix. So the alpha helix is a rod like structure as shown on the board, that contains the backbone being in the inside of that helix and the side chain groups on the outer portion of that helix. Now, let's suppose that this is our axis of rotation.