Just as remarkable as our internal structure is our external wall. My membrane is a bare .0000001 millimetre thick. Until very recently, scientists thought of this gossamer covering as little more than a kind of tight cellophane bag. Thanks to the electron microscope, they now realize that it is one of my most important components. Acting as gatekeeper, the cellular membrane decides what shall be admitted, what excluded. It controls the cell’s internal environment - keeping in exact balance salts, organic materials, water and other substance. Life is absolutely dependent on this.
Tags: Cell, internal structure of cell