And likewise, we have the peripheral protein that we find on this side and don't find on the other side. Number two is we have asymmetry because of the difference in the positioning and the orientation of proteins. For instance, if we look at this transmembrane protein, this is oriented in such a way so that this side only contains the peripheral component protein and not this side. And number three is there is asymmetry as a result of a difference in the enzymatic activities of the two sides. Basically, those reactions that take place on this side of the membrane don't take place on this side and vice versa. For instance, if a protein needs to use ATP molecules, the ATP molecules are only found in the cytoplasm.