So I have to apply force, I have to move this and do works, I have to transfer energy. And in the same exact way, these membrane pumps utilize energy to move these ions and molecules against their electrochemical gradient from a low to a high potential. And because they use energy, we call them active transporters. So this type of mode of transport is known as active transport. So unlike channels, pumps utilize energy. So the energy can be the energy stored in the chemical bonds of ATP molecules.