THE CELL MEMBRANE

The cell or plasma membrane separates extra- and intracellular compartments.
The cell membrane allows a bidirectional, dynamic and selective exchange of organic molecules, ions and gas molecules between both compartments.
Note that a unique cell may be in contact with two different types of extracellular compartments. This is the case for epithelial (intestin, nephron) and endothelial cells.
The cell membrane's molecular structure is tightly linked to its highly diverse roles and functions.

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