Okay, so there are essentially five different steps in this process. And let's begin with this diagram right here. And notice so this is our membrane, the phospholipid bilayer, and this is our protein pump, our ABC transporter. And this diagram that basically describes this transmembrane pump in its closed state. And what that means is the substrate molecules cannot actually enter this molecule. Now, what happens is it basically inter converts from the closed state and the open state.