Label the parts of a cell membrane with the term that describes each part.

The basic structure of a cell membrane is in three parts; the internal membrane surface, the external membrane surface and the intervening phospholipid material. This intervening material is impermeable to ions and polar molecules and it prevents polar solutes likie amino acids from moving across the membrane but permits the passive diffusion of hydrophobic molecules ... The external and internal cell membranes are selectively permeable and can regulate what comes into or goes out of the cell and in so doing allows for the transport of materials needed for survival.