DNA+Structure

DNA Contents
 * [|General]
 * 1[| DNA->Scientists]
 * 2 DNA->Structure
 * 3 DNA->Replication
 * 4 DNA->RNA Structure
 * 5 DNA->Protein Synthesis
 * 6 DNA->Transcription
 * 7 DNA->Translation
 * 8 DNA-> Mutation
 * 9 DNA-> Practice Quiz

=DNA Structure - Video Podcast= media type="custom" key="34702"

=Study Guide Questions= Watch the video podcast, read your book on DNA Structure and collaborate with your fellow classmates to answer these study guide questions.

2. Describe each of the base components that make up DNA. Be sure to include the scientists that discovered this structure and the base pairs that make up DNA.

By the 1950s, there was a competition between scientists --- Watson and Crick vs. Franklin and Wilkins --- to discover what DNA actually looked like and how it was structures. Watson and Crick, at Cambridge, devised their work on building a 3 dimensional structure while Wilkins and Franklin, at King's College, employed difractional x-ray images of DNA. So far, Franklin had the best discoveries when she suspected that DNA might be a helical structure since he x-ray images revealed such a structure of DNA in its "wet form." Unfortunately, Wilkins backstabbed Franklin and showed her results to Watson and Crick, whom now began devising their concept of DNA as two chains of nucleotides(one strand going up and the other down) that should form a double helix or similar helical structure. In addendum, another necessary finding was made by Erwin Chargaff who had very important findings about base pairs. Along with Chargaff's findings, Watson and Crick inserted the interlocked base pairs (AT/CG) between the 2 nucleotide strands and voila: DNA. (Watson, Crick, and Wikins got the Nobel prizes except Franklin who already had died and you need to be alive in order to actually get the award back then)

3. What is a Nucleotide? What three components are in each nucleotide? Which direction does a new strand of DNA run?

Nucleotides are monomers(single units) of nucleic acid(polymer) that are the building blocks of DNA/RNA. The direction that the new strand of DNA runs is from 3 to 5. The three components of a nucleotide are a ring-shaped sugar called deoxyribose, a phosphate group, and nitrogenous bases.

4. What shape does DNA make? Who contributed to this discovery?

The double helix model was technically credited to Watson and Crick(concerning the Nobel Prize). Nonetheless, evidence shows that Franklin first discovered the helix in her results from the difractional x-ray images. However, she only figured out that the structure was a helix, but not a double helix. Nevertheless, she was never published or directly announced her findings while Wilkins showed those findings to Watson and Crick. They then finally finished a double helix 3D structure of DNA thanks in part to Franklin's findings.

5. What are Purines and Pyramidines?

Purines and Pyramidines are nitrogen-containing bases that are the building blocks of nucleic acid. The Purines are Guanine and Adenine are purines (which have two rings), then Thymine and cytosine are pyramidines(one ring). Most importantly, the purines and pyrimidines come to form pairs composed of one purine and one pyrimidine, such as guanine-cytosine and adenine-thymine.