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10 Cards in this Set
- Front
- Back
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Who discovered DNA and when?
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Friedrich Miescher in 1869
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Who provided the first evidence that DNA is the genetic material? What did they do?
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1944: Avery, McLeod and McCarty identified DNA as the chemical substance responsible for changing rough, nonvirulent cells of S pneumoniae (R) into a smooth encapsulated infectious cells (S)
A) Purified DNA extracted from heat-killed S cells can convert some living R cells into S cells, but the extract may still contain undetectable traces of protein and/or RNA B) The transforming activity is not destroyed by either protease or RNase. C) The transforming activity is destroyed by DNase and so probably consists of DNa |
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What is Griffith's experiment? What did it demonstrate?
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Griffith's experiment demonstrated bacterial transformation.
-Inject mouse w/ living pathogenic S cells = contract pneumonia and die. -Inject mouse w/ living R cells = mouse healthy -Inject mouse with heat killed S-cells = mouse healthy -Inject mouse with heat killed S-cells + R cells = mouse dies. |
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What did Watson and Crick do?
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1953: Proposed the 3-D helical structure of DNA.
-Double stranded helix comprised of a linear sequence of paired subunits = nucleotides |
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What nucleotides are in DNA and what pairs do they make?
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Adenine + Thymine
Cytosine + Guanine |
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Which nucleotides are purines and which are pyrimidines?
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Pur As Gold
Cut The Py Purines = Adenine, Guanine Pyrimidine = Cytosine, Thymine |
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How do you differentiate the structures of Purines vs. Pyrimidines?
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Purine = 2 rings
Pyrimidine = 1 ring |
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What is the genetic code?
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The mRNA decoding table. A triplet code.
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How many total codons are there?
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64
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What are the stop and start codons?
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Start: AUG- methionine
Stop: UAA, UAG, UGA |
