Double MembraneThe double membrane is another name for the lipid bilayer membrane around the cell. This membrane is a self-constructing layer of lipids dotted with proteins and other critical molecules, with the hydrophilic ends arranged in one layer and the hydrophobic ends arranged in the other layer.
The hydrophilic end is attracted to water, but will repel oily substances. The hydrophobic end does exactly the opposite – it repels water and anything dissolved in water while attracting oils.
This double membrane structure is critical to the success of a cell. With the other molecules embedded in the double membrane, the alternating layers of water repulsion and oil repulsion allow the cell to remain impermeable, while still letting desired substances in using proteins and other molecules as gateways.
Lipids are very self-organizing; with the appropriate concentration of substances, certain lipids left alone will form a bilayer, the building block of the double membrane. The hydrophobic ends tend to be attracted to one another, and form a core, while the hydrophilic ends face the watery solution outside the membrane. This structure allows in small hydrophobic solutes but generally does not accept inorganic ions or other hydrophilic molecules.
Web Resources On Double Membrane
Cell Membrane Animation
Eukaryote Cell: Organelles - Membrane Bound
Book Resources On Double MembraneElectrical Double Layers in Biology by Martin Blank
Methods and Results in Crystallization of Membrane Proteins by So Iwata (Editor)
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