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14 Cards in this Set
- Front
- Back
The Genetic Material Must Exhibit what Four Characteristics
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-replicate
-store information -express information -allow variation by mutation |
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Why was protein favored as the genetic material?
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-It is abundant in cells.
-It was the subject of the most -active areas of genetic research. -DNA was thought to be too simple to be the genetic material, with only four types of nucleotides as compared to the 20 different |
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Evidence for bacteria
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-BACTERIA: transformation (Griffith, then Avery McLeod and McCarty)
-Phage: Hershey and Chase |
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RNA is
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genetic material in some viruses
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Nucleotides
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-Building blocks of DNA
-Consist of: -nitrogenous base -pentose sugar -phosphate group |
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Nitrogenous bases can be
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Purines-adenine, guanine pyramidines-cytosine, thymine,uracil
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DNA and RNA sugars
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RNA sugar- Ribose
DNA- Deoxyrybose |
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Nucleoside
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contains the nitrogenous base and the pentose sugar
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Nucleotide
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-a nucleoside with a phosphate group added
-can have 1,2 or 3 phosphate groups called NMP's,NDP's, NTP's Respectively |
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C-1' Position
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location
of the nitrogenous base on a nucleotide/nucleoside |
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C-5'
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location of the phosphate group on a nucleotide
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Nucleotides are linked by
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phosphodiester bond between the phosphate group at the C-5' position and the OH group on the C-3' position.
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X-ray diffraction:
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showed a 3.4 angstrom periodicity, characteristic of a helical structure
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Watson and Cricke Model
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-2 polynucleotide chains coiled around a central axis – form a right hand double helix
-Major groove alternates with a minor groove -Diameter of helix is 20 A |