And so that protein component can only interact with the ATP from the cytoplasmic side of the membrane, as we'll discuss in more detail in just a moment. Now, why is asymmetry so prevalent? So every single plasma membrane basically is asymmetric. 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.