A Piece of "Fluid Membrane"


A portion of a phospholipid bilayer membrane is shown using the Spacefill display. This structure corresponds to the least ordered arrangement of the phospholipids, the so-called "fluid" phase. Similar displays of the crystal and gel phases show more order in the fatty acid tails of the phospholipid.

"Dissect" the structure as follows to see specific portions of the bilayer:
Color the carbon atoms in the lower layer a darker gray.

Remove all of the H2O molecules.
  Add the H2O molecules back to both sides of the bilayer.

Show a chunk of the upper layer as Wireframe.
  Remove a chunk of the upper layer completely.
  Restore the chunk of the upper layer to its original Spacefill display.

Viewing Tip: Rotate the model after each of the above operations to get a 3-D perspective on the way the various portions of the bilayer are related to one another.

Back to Molecules for Modern/Cell Biology at CMU.

The image displayed on this page requires the Chemscape Chime plug-in.
A description of its use at this site can be found at the Chime Features page.

Credits: The coordinates are from the work of H. Heller, M. Schaefer, and K. Schulten (1993) "Molecular dynamics simulation of a bilayer of 200 lipids in the gel and in the liquid-crystal phases", J. Phys. Chem. 97, 8343-60.
See also Dr. Eric Martz' treatment of Lipid Bilayer Membranes to view GIFs of the crystal, gel and fluid models and for downloading the coordinates of each.