More than one expert has observed that musicals with great scores and weak books tend to fail, while those with mediocre scores and solid books have a better chance of succeeding. After all, the first job of every play or film  musical or not  is to tell a good story.
Cell membrane. The cell membrane (also known as the plasma membrane or cytoplasmic membrane) is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells.
Review of Membrane Biology. In all cellular organisms, the plasma membrane is the outermost layer of a cell. It serves to separate the cell from the external environment. In prokaryotes, it is the only membrane.