In the fluid-mosaic model that describes cell membranes, ________.
◦ two layers of phospholipid molecules have their nonpolar sections oriented to the inside of the membrane
◦ there are three layers of phospholipid molecules
◦ a single row of phospholipid molecules forms a barrier between the inside and outside of the cell
◦ two layers of proteins separate the contents inside a cell from the surrounding fluids
◦ two layers of phospholipid molecules have their nonpolar sections along the outer surface of the membrane