So let's suppose we take the sodium ions one more. So we have a high concentration, a low concentration electric field lines basically point in the direction. That means these sodium ions want to move naturally from a high potential to a low potential. But now we're looking not at a channel, but at an ATPase, a pump that uses ATP. And so what this does is it uptakes an ATP molecule from the inside, it hydrolyzes that ATP molecule. And that creates a conformational change in the structure of that pump.