1. NOTES: NOTES: DNA Experiments & Structure Monday 3-8-2010

2. (1) Griffith’s Experiment: Question: What about a “disease” kills animals? Experiment: –Injected some mice w/dead bacteria –Injected some mice w/dead disease bacteria, and living normal bacteria Results: –Mice w/only dead bacteria  No Disease –Mice w/Mixture  Disease –“Disease” carried in some molecule, which was passed on to the living-normal bacteria!

4. http://www.quia.com/files/quia/users/hlrbiology/An imations/08_DNA_and_Proteins/Griffith_Mouse _Experiment.swf

5. (2) Hershey-Chase Experiment: Question: Does DNA or Protein contain genetic information? Experiment: –Dyed the DNA, and the protein in viruses. –Infected bacterial cells with the viruses. Results: –DNA ended up inside the bacteria, and made more viruses. –Protein stayed outside the bacteria. –DNA contains genetic instructions, not protein!

8. http://highered.mcgraw-hill.com/olc/dl/120076/bio21.swf

9. (3) Wilkins & Franklin’s Experiment: Question: What is the overall shape of DNA? Experiment: –Shot X-rays at DNA crystals –Recorded the ray-pattern Results: –Produced an X-Ray diffraction photograph. –Saw an uneven, X shape. –DNA is a double helix with minor and major grooves!

12. (4) Watson & Crick’s Experiment: Question: What is the chemical structure of DNA? Experiment: –Pieced the DNA compounds together like a puzzle. Results: –Phosphate and Sugar alternate on the outside of DNA. –Nitrogenous Bases are inside the helix. –Adenine forms 2 hydrogen bonds w/Thymine. –Guanine forms 3 hydrogen bonds w/Cytosine.

15. (5) Nucleotide: Nucleotide:Nucleotide: The monomer of a nucleic acid (like DNA). Made Of: –1-Phosphate –1-Sugar –1-Nitrogenous Base

16. (6) DNA Structure: Double Stranded Double Helix Anti-parallel strands DNA Nucleotides:DNA Nucleotides: –Phosphate –Deoxyribose Sugar –Nitrogenous Bases: A = Adenine T = Thymine G = Guanine C = Cytosine

18. (7) Anti-Parallel Strands Anti = Opposite Strands are flip-flopped from one another One Strand’s 3’ End, matches the other’s 5’ End!

19. (8) Chargaff’s Rule: Adenine ---- Thymine –%A = %T Guanine ---- Cytosine –%G = %C (A+T) + (G+C) = 100%(A+T) + (G+C) = 100% –Use this to determine percentage of types of bases.