Cell membrane

The cell membrane is a thin flexible layer around the cells of all living things. It is sometimes called the plasma membrane or cytoplasmic membrane.

Its basic job is to separate the inside of cells from the outside.^[1][2] In all cells, the cell membrane separates the cytoplasm inside the cell from its surroundings. Animal cells are contained in just a membrane. Bacteria, fungi and plants have strong cell walls as well, which support the cell and block the passage of large molecules.

1. ↑ Kimball's biology pages Archived 2009-01-25 at the Wayback Machine, Cell membranes
2. ↑ Singleton P (1999). Bacteria in biology, biotechnology and medicine (5th ed.). New York: Wiley. ISBN 0-471-98880-4.