BNFO 300 
Molecular Biology Through Discovery
Path to class (Tuesday, Sep 24) - Meselson and Stahl Experiment
(please press SUBMIT button when finished)
Fall 2019  


My advice on the matters for the day (as listed in the calendar):

DNA
  • Meselson & Stahl (1958): Many people have learned of this experiment in previous classes. They say "I already know that DNA replicates semiconservatively". Is that right? HOW do you know that? Understanding the experiment that led to a concept will generally make a fuzzy concept tangible. Today is your chance. Do what you need to do to understand the experiment or, failing that, to develop questions that will lead you to understanding. The companion to the article and its study questions may help, particularly Study Questions 2, 7, 9, and 14.
     
  • Exam 2: Take a look at the ground rules and what to expect, and please return the form regarding your availability.
     
  • Problem Set 4: Look over Problem 4.6 before class if you like, or wait until you meet with your groups. It might be helpful before class to familiarize yourself with the Polymerase Chain Reaction, perhaps using the links given in Problem 4.6 to a tutorial
     

I. Basic Information

  1. Your name  
II. Old business (no need to repeat anything you've said in a previous questionnaire)
  1. DNA Structure
    Anything further you'd like to discuss regarding the notes DNA Structure?
    OK with the nature of palindromes? If not, describe your current state of understanding.

     
  2. DNA Replication
    Anything further you'd like to discuss regarding the notes DNA Replication?
    OK with the directionality? Primers? If not, describe your current state of understanding.

     
  3. How to read a research article
    Anything further you'd like to discuss regarding the mini-article (describing an experiment concerning DNA replication) and the suggestions how to go about reading it (and any research article)?

     
  4. Summary of an experiment from a research article
    On Tuesday, October 1, you will present a poster that summarizes an experiment from a published research article. Are you clear on how to find an experiment and how to develop a summary?
III. Meselson and Stahl
  1. How far have you gotten in Meselson and Stahl (1958) and its companion?

     
  2. Consider how comfortable you are with the following topics regarding Meselson & Stahl:
     
    • The topological problem implicit in the replication model presented by Watson and Crick
    • Dispersive replication, and how it addresses the topological problem
    • The critical differences between the three featured models of DNA replication
    • How heavy isotopes can distinguish new from old DNA
    • What properties of cesium chloride are helpful in this procedure
    • Equilibrium density centrifugation
    • How to read Fig. 4 (e.g. what do position and ultraviolet absorption indicate)
    • The relationship between Meselson and Stahl's results and the predictions of the three featured replication models
    • How Delbrück's topological problem was ultimately resolved

    Please relate your thoughts and current state of understanding
IV. Miscellaneous
Any other comments, questions, suggestions, or concerns you may have?

Thanks!

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