And so these pumps are known as active transport as they use these ATP molecules and energy to actively move these molecules against their electrochemical gradient. Now, there are two types of membrane proteins. We have two types of membrane pumps. So we have membrane pumps that use ATP molecules as the energy source molecules and they use them directly. And these are known as Atpas. So pumps that utilize ATP directly, hydrolyzed ATP, are known as Atpas.