So there are electric field lines that exist within the cell membrane. And what that means is there is a certain amount of energy that is storage that is stored within the electric field that exists inside the cell membrane. So four important functions act as a protective barrier, basically acts in transport, in signal transduction, as well as energy storage. Now, every single cell inside our body contains this cell membrane and all these cell membranes have the same properties. So let's examine what these properties are. Property number one is these cell membranes are relatively thin and they enclose that entire cell.