What is the biological significance of cell membranes in cells?
The cell membrane or plasma membrane or cytoplasmic membrane is a biological membrane which separates the interior of a cell from the external environment. It thus protects the contents of the cell from external forces.
The cell membrane consists of a lipid bilayer embedded between phospholipids and a protein layer. The lipid bilayer maintains the fluidity at various temperatures while the protein layer serves as a membrane transport amongst other functions.
The cell membrane is thus selectively permeable to ions and organic molecules and its primary role is to control movement of substances in and out of the cell.
Other functions include: