MOLECULAR STRUCTURE OF THE CELL MEMBRANE

Total thickness: about 75 nm, but this may vary with cell types.

Composition: two lipidic layers containing proteins associated to extracellular sugars.
 
Microscopic structure : It is a continuous envelope.
When seen by electronic microscopy, the cell membrane displays three layers: 2 hydrophilic layers set on both sides of a hyrdrophobic layer.

The hydrophobic layer has a thickness of around 3.5nm.

The outer hydrophilic layer, which is in contact with the extracellular compartment is composed of a network of polysaccharides (called glycocalyx or cell coat).
The inner hyrdrophilic layer is in contact with elements of the intracellular cytoskeleton.
Each one of these layers is about 2nm thick; however, the outer layer is often thicker than the inner layer and can reach 200 nm in some cell types, such as enterocyte cells.

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Related topics : cell membrane sugars, cell membrane proteins, lipid, sugar and protein-related properties of the cell membrane