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. So the axis of rotation along which that alpha helix actually forms runs along the x axis in this direction. So this is the beginning of our polypeptide and this is the end. So we see that in this case, we go into the board, then we come out of the board, we go into the board, out of the board, we go into the board, out of the board, we go into the board, out of the board, and so forth.