DNA Structure
An Interactive Animated Nonlinear Tutorial by Eric Martz
Also available "en Español", "auf Deutsch", "em Português".

Version 3.0 works in Internet Explorer (Windows only)
or Netscape (Windows or Macintosh). (Translations of earlier versions may require Netscape.)
More tutorials on DNA and proteins, in English, Spanish, etc., are indexed at molvisindex.org.
Check the original source periodically for updated versions. See the version history.

  1. Please check your browser and Chime plugin version for compatibility before proceeding.
    If you see a pink ball inside a black square to the right, the Chime plugin is installed. If the ball turns green (and gets smaller) when you click the link "Small & Green" (not here, at the right), your installation should work with the DNA tutorial below. (Clicking the gray X button marked "Large & Pink" should restore the pink color and larger size.)

    If there is NO pink ball, or NO black square, or it does NOT change when you click "Small & Green", please click here for free browser upgrade and troubleshooting help!

    Small & Green

    Large & Pink

  2. This tutorial is designed to complement an introduction to DNA by providing tools for a self-directed exploration. It does not tell a story (but does offer questions for students and a lesson plan for teachers). As a preamble to the tutorial below, or for a story that introduces DNA Structure with interactive molecular graphics, we recommend Exploring DNA Structure by Andrew Carter (which also requires Chime, and works in Internet Explorer), or other DNA links. This entire website, along with other molecules, is available online (BioMolecular Explorer 3D) or on a CD designed for high school teachers.

  3. The Animated Interactive Tutorial Pages (A, B, C, D):
    Please use a large window for these (full-screen if your screen resolution is 800 x 600 or less)!
A. Double helix by element:
base pairs, hydrogen bonding

B. The Code

Explanation of
Codons and

C. Strands and helical backbone

D. Ends, Antiparallelism

  1. Questions for Students and a Lesson Plan for Teachers.
    More Molecules for High School Teachers!

  2. More DNA Resources include tutorials for high school students, college freshmen, interactive Shockwave simulations of agarose gel electrophoresis to learn about electrical charge of DNA, cutting with restriction endonucleases, etc.

  3. You can download a copy of this tutorial. Once you have your own copy on your computer's hard disk, you can use it offline (without an Internet connection).

  4. How can I get the most out of Chime?
    Please note that in most images, double bonds are shown as single bonds, and hydrogen atoms are missing.
    If you know how, it is OK to use Chime's menu to change the image, but afterwards you should push the Reset button. Otherwise other buttons may give undefined and incorrect results.

  5. Methods, Acknowledgements, and References. If you are interested in developing a new nonlinear Chime tutorial, try the Development/Debugging Mode, and read this section, especially the instructions provided.
Have you seen the tutorials on hemoglobin, lipid bilayers and channels, antibody, and other molecules at MolviZ.Org? Feedback/Requests to Eric Martz.

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Available since 1996!