Population Statistics within the Arizona Department of Administration and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes no guarantees, warranties,
The Cell Membrane. The Structure of the Cell Membrane. The cell membrane (or plasma membrane) surrounds all living cells, and is the cell's most important organelle. It controls how substances can move in and out of the cell and is responsible for many other properties of the cell as well.
Both the cell membrane and the cell wall serve this function. All cells have a cell membrane, and certain cells (plant and bacterial) also have a cell wall. The cell membrane's main function is to regulate the movement of materials into and out of the cell. During plasmolysis, the cell membrane pulls away from the cell wall. 2  This does not happen in low salt concentration because of the rigid cell wall. 3  Plant cells maintain their normal size and shape in a low salt concentration solution.