Now, all types of pumps are energy transducers and what that basically means is they transform energy from one form to another. So in the case of ATP Aces, they transform the energy stored in the chemical bonds of ATP into the energy stored in establishing that electrochemical gradient. So we see that membrane pumps are responsible for actually using ATP or energy to create establish these electrochemical gradients. And then the membrane channels use these gradients to basically move these molecules spontaneously from one side to the other side down that electrochemical gradient. So we said a moment ago that we have two types of pumps. We have ATP Aces and we also have second air transporter.