So we have the oxygen that is more electronegative than the carbon and it develops a partial negative charge. And so if an H atom that has a partially positive charge is found in close proximity on the other side of this partially negative oxygen, then we have a bond that is formed and that bond is a hydrogen bond. And so this oxygen is said to be an acceptor of that partially positive H atom. 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.