Hand in W.S. Tuning in to radioisotopes

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Class Topics
Title Biology 3/14/07
Objectives

• To learn about the historical discoveries
  surrounding the genetic material, DNA.

• Hand in W.S. Tuning in to radioisotopes
• Check Grade Sheets
• Review Chapter 9 Quiz 1
• Review DNA structure Photo 51
• Notes Chapter 9
• "No one can make you feel inferior without your
  consent."
• Eleanor Roosevelt

Wednesday, July 22, 2015 1150 AM
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Class Assignments
By When
What

• W.S. Tuning in to Radioisotopes 3/14/07
• Read 194-200 3/14/07
• W.S. 9.2 3/16/07
• Doublin DNA 3/16/07
• Due this class period
• Due next class period
• Due in the future

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Grade Sheet
2A p. 157 (5 pts.)
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Rosalind Franklin

• 1951 - X-ray diffraction
• Maurice Wilkins
• Suggested that DNA was two strands
• Tightly coiled helix
• Photo 51, flash

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From http//www.pbs.org/wgbh/nova/photo51/pict-01
.html
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Watson and Crick

• James Watson (American) and Francis Crick
  (British) discovered the shape and organization
  of DNA
• Double helix
• two strands
• sugar/phosphate backbone
• nitrogenous bases in middle
• Won Nobel Prize for DNA model
• with Maurice Wilkins

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Replication (PBS)

• DNA double helix (like a spiral staircase) is
  easily replicated (doubled)
• Occurs during S phase of cell cycle
• 1. Enzyme, DNA helicase, attaches to DNA
  molecule
• Hydrogen bonds between strands break (DNA unzips
  and unwinds)
• Forms replication forks
• Areas where the strands separate

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Replication (DNAi)

• 2. DNA polymerase bonds free nucleotides
  (floating in nucleus) to exposed nitrogen bases
• adenine to thymine guanine to cytosine
• 3. Hydrogen bonds formed between nitrogen bases
• Proofreading
• DNA polymerase can go back and check for errors
• 1 error per 1 billion nucleotides

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Lab Doublin DNA

• Procedure 1 and 2 cut out the nucleotides
• 3. Use the DNA strand
• GTCAACTG
• 4. Have work checked after 4
• Pick up your homework W.S. when done.