Why? Well, asymmetry is actually crucial for the proper functioning of that membrane. So to see what we mean to demonstrate, let's study the ATP or the sodium potassium ATP pump found in every single cell of our body. So this is what it basically looks like. And what it is is it's this pump that utilizes ATP molecules to create an electrochemical gradient and it pumps the sodium ions to the outside and the potassium ions to the inside. Now, because it uses ATP molecules, ATP molecules are only found in the cytoplasm.