Now, another terminology that you have to be familiar with in your study of biochemistry is what it means for a group of atoms to be an H bond donor and what it means to be an Hbond acceptor. So if we examine the following interaction this group of atoms is our H bond donor and this is the Hbond acceptor. This is the H bond donor and this is the H bond acceptor. So an Hbond donor is basically that group of atoms that contains the intramolecular bond between the electronegative atom and that H atom. So this if we zoom in on just this diagram this is our intramolecular bond that exists between these two atoms. And so this is the H bond donor and the other atom that contains that partial negative charge is the H bond acceptor.