DNA Notes: Ch. 9

KEY WORDS/

QUESTIONS / NOTES
Historical Perspectives
Who’s who?
(Great site for the history and experiments!) / 1. Frederick Griffith: The Griffith Experiment (1928)
Purpose: “Accidental” unexpected discovery of bacterial transformation: Hereditary info can be passed between cells.
How: Figure 9.1!!! Set up four mini-experiments in one dealing with mice and the bacteria Streptococcus pneumoniae. One type of bacteriadeadly, other typeharmless. But he found that he could render the deadly version harmless if he heated it, but at the same time he found that in experiment 4 (see figure) he could still get dead mice.
Take Home Point: Something is changing the bacteria from bad to good & vice versa...was it proteins or DNA???
2. Oswald Avery/Colin MacLeod/Maclyn McCarty: The Avery Experiment (1944)
What: A follow up to the Griffith experiment...but this time they took proteins out of the mix, to see if it was the DNA that was causing the change. Yep...it was!
3. Alfred Hershey/Martha Chase: The H-C Blender Experiment (1952) (Online Book Animation)
In 1952, the Hershey-Chase experiments used radioactive labels to individually mark the DNA and the protein of viruses.
They labeled the DNA of the viruses with radioactive phosphorus, while they labeled the protein coat with radioactive sulfur.
They infected bacteria using these radioactive viruses, and found the bacteria contained the radioactive phosphorus, but not the sulfur.
This was additional evidence that DNA was the genetic material.
4. Watson/Crick:
5.Rosalind Franklin:
6.Erwin Chargaff
Structure of DNA (185) / Monomer: Nucleotides
Purines: G/A
Pyrimidines: T/C
Polymer: DNA & RNA
Similarities and Differences between DNA/RNA
DNA RNA
Draw your own unique structure of DNA with at least 12 nucleotides:
KEY: Antiparallel Strands so that the bonds between the bases can line up.
Replication of DNA (204)
Alternative Mechanisms of DNA Replication: (Fig. 9.5)
  1. Conservative
  2. Semiconservative
  3. Dispersive
So which way is the correct way? An experiment by Meselson & Stahl in 1958 settled the question: Semiconservative!!! (Don’t worry about the experiment!) /
Key terms/Enzymes to cover: (I don’t plan on teaching this in AP... just providing a BRIEF review!)
*Leading & Lagging Strands and why they occur: the polymerase can only read the DNA in one direction...so if the sides run opposite the polymerase has to read opposite on one side.
*Helicase
*DNA Polymerase
*Ligase
*SSBP: single stranded binding proteins to keep the DNA open during replication
*Primase
Accuracy & Repair: (189) /
  1. What is a mutation?
  1. Types of Mutations:
  1. Fixing Mutations: