The Molecular Basis of Heredity - The Structure of DNA

Activity: DNA - An introductory level nonlinear self-paced tutorial.
Chime Resources, by Eric Martz, University of Massachusetts, Amherst http://www.umass.edu/microbio/chime/dna/fs_pairs.htm

Directions: First, let's explore the functions of the tutorial. Then, using the DNA tutorial, answer the following questions.

1. Starting from either end of the strand of the DNA, list, in order, the nucleotide bases. (2pts.) (GC, GC, GC, AT, GC, GC, AT, GC, AT, GC, AT, GC, GC, AT, GC, GC, GC)
   
2. Click End. Look at the DNA strand from the end, is it symmetrical? (2pts.) (Yes, it is symmetrical.)
3. Click H Bonds. What are the H bonds and where are they located? (2pts.)
   ( H bonds are the hydrogen bonds between the nucleotide bonds.)
4. Click Backbone. Click Side. Click X spin. What do you notice about the symmetry of the two strands? (2pts.)
   ( Not symmetrical, there is a minor groove and a major groove.)
5. Right click on the structure of DNA. Click Display. Click Sticks. Right click on the structure of DNA (again). Click Options. Click Dot surface. Click Van der Walls Radii. What do you think the fuzzy looking dots represent? (2pts.)
   ( Electron field around atoms)
6. Click Spacefill. What do the solid balls represent? (2pts.) (Atoms and their electron fields)
7. How are the nucleotide bases arranged in the DNA? (2pts.) (Stacked on top of one another)
8. What is your favorite view of the DNA and why? (2pts.) (Answers may vary.)
9. Click Backbone. Draw the structure of the backbone using colored pencils (in 2-D). Indicate which color represents the elements. (6 pts.)
   (Oxygen = red, carbon = gray, phosphorous = yellow.)
10. In your own words and in complete sentences (you may also draw a diagram with colored pencils too), describe the structure of DNA. Make sure you include all of the terms we discussed in lecture and during the tutorial. (25 pts.)
    (Double helix, major and minor groove, phosphate backbone, five-carbon sugar, nucleotide bases, purines, pyrimidines, adenine, cytosine, guanine, thymine, hydrogen bonds.)

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