This tutorial is intended to supplement your biology or biochemistry
textbook. It is not a complete introduction to DNA structure by itself.
This tutorial is still under development. Check the
periodically for updated versions. See the version
history at the bottom of this page.
Please note that in most images, double bonds are shown as
single bonds, and hydrogen atoms are missing.
To stop a slow spin, click the Reset button.
It is OK to use the mouse to change the image, and to use Chime's
menu, but beware that if you subsequently push buttons other than
the Reset button, errors may result.
download a copy of this tutorial.
Once you have your own copy on your computer's
hard disk, you can use it without an Internet connection.
Have you seen the
other Chime resources at UMass?
Feedback/Requests to Eric Martz.
This tutorial requires
Chime 1.0 and Netscape Navigator 3.01/3.02/4.01.
IE 3/4 and earlier versions of Navigator will not work properly --
How can I get the most out of
Double helix by element: base pairs, hydrogen bonding
Strands and helical backbone
Further information on DNA (Not yet implemented.
Send your suggestions for this section to
Methods, Acknowledgements, and References.
If you are interested in developing a new nonlinear Chime tutorial,
try the Development/Debugging
and read this section, especially the
- 98/01/24, version 2.3:
Made compatible with Navigator 4.04 and Chime 2 under Windows 95..
- 97/07/25, version 2.2: Made compatible with Navigator 4.01. AT
and GC buttons on base-pairs page are now toggles, first extracting,
then reinserting the base pair into the helix. New explanation pages
linked to color keys. Button backgrounds made gray (instead of
black) so Navigator 3.01's all-black mouse pointer text bar is
visible. (Bar is black and white in 4.01.) All documentation
was brought up to date.
- 97/01/22, version 2.01: Several bugs fixed.
- 97/01/21, version 2: AT/GC as ball-and-stick with double bonds, hydrogens
optional. 2X and 1/2X improved. Instructions for creating new nonlinear
tutorials. Debug mode provided. NonLinear Control Structure version 2
(NLCS2). Many other improvements and bugs fixed.
- 96/11/11, version 1.5: Improved AT/GC button results. Added one question as demonstration.