On the left in the table
below you can view some rotatable 3-D images of assemblies of
molecules using the Jmol java applet. This is an example of one
the simple interactive pages that can be generated using the
"Molecules" choice in the java
Molecular assemblies are held together by relatively strong
In the case of water the dominant interactions are hydrogen bonding and
dipole-dipole interactions. In ice the hydrogen bonding results
in a rigid stucture where each water has the same orientation relative
to its neighbors. In melting ice, many of the hydrogen bonds are
ruptured and less order is apparent. Notice that ice has large
holes between the molecules; thus ice has a larger volume than the same
amount of liquid water.
In the case of lipid bilayers (cell membranes are an example) one of
the dominant interactions is the
van der Waals attractions between the long alkyl tails of the
lipids. The structure of the lipid bilayer also depends on the
polar interactions between the water at each side of the bilayer and
the polar head groups.
generated by a java program (Jmol_Web_Page_Maker)
on Jul 16, 2006.
page composed by J.
for using Jmol to display
- Choose which molecules to display by selecting them using
popup menus or clicking on the appropriate link.
- ROTATE the image by
down the mouse button while moving the cursor over the image.
- ZOOM by holding down the shift key while moving the cursor
(decrease magnification) or down (increase magnification) on top of the
- Other options are available in the control menu accessible
the mouse button down while the cursor is over "Jmol" in the lower
right corner (right click also works on a multibutton mouse).
- For more info about Jmol go to www.jmol.org.
J. Gutow 7/2006
Last Update: 7/21/2006