Cell membranes

Membrane Structure

Membranes that are within cells and surrounding them consist of:

• a phospholipid bilayer 
• protein

In an aqueous environment, phospholipids arrange themselves into bilayers so that the hydrophobic (fatty acid) 'tail' regions face inwards so that they are sheilded from the surrounding polar fluid. This causes the hydrophilic (phosphate) 'head' regions to associate with the cytoplasmic and extracellular faces on either side.

The phospholipid bilayer is the…