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. In all cells, the cell membrane separates the cytoplasm inside the cell from its surroundings.
Biological membranes have three primary functions: (1) they keep toxic substances out of the cell; (2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the ...
Cell membrane. ... Enclosed by this cell membrane (also known as the plasma membrane) are the cell's constituents, often large, water-soluble, highly charged molecules such as proteins, nucleic acids, carbohydrates, and substances involved in cellular metabolism.
