:james watson and francis crick, along with maurice wilkins, won the nobel prize in 1962 for discovering the structure of dna.  many people trailblazed for them:
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 :fred griffith - 1920s - did an experiment with mice to help people dying with pneumonia from bacteria.  he injected mice with 2 strains of pneumonia (r-strain had a rough coat and the s-strain has a smoothe lipid-layer coat) the s-strain was deadly to the mice.  when he heat-killed the s-strain and injected the mice, they lived.  when he mixed the heat-killed s-strain and the r-strain, the mice died (after death, he found a live smoothe type in the mouse)
 :transformatin - a change in phenotype due to assimilation of external genetic material
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 :avery and mccloud - 1944 - examined griffith's experiment.  griffith said that protein was the passing-on agent but avery and mccloud decided that dna was the genetic material, not protein.
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 :chargraff - 1947 - biochemist who found ratios of the nitrogen bases (the amount of adenine  was almost equal to that of thymine and  guanine and cytosine were relatively comparable)
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 :hershey and chase - 1952 - performed radioactive isotope experiment to confirm avery and mccloud's findings
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 :maurice wilkins - performed an experiment using x-ray crystalography
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 :Origin of Replication:
 : -specific proteins bind to origin
 : -helix opens and replication forks spread in both directions
 : -bacterial and viral DNA have only one origin
 : -eukaryotic: 100s or 1000s of replication origins
 :elongating the dna strand
 : -helicases (enzymes) catalyze unwinding
 : -single strand binding proteins - keep strands apart and stabilze
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 :synthesis of the new strands
 : -dna polymerase
 : -grow 5' to 3' direction
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 :nucleoside triphosphate:
 : -provides the energy necessary  to synthesize the new DNA strands
 : -they are the dna building blocks; they lose 2 phosphates when they form covalent linkages to the growing chain
 : -exergonic hydrolysis
 : -leading strand (contiunous strand)
 : -lagging strand (discontinuous series of okazaki gragments linked by dna ligase
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 :Errors:
 : -only 1 in 1 billion errors
 : -"mismatch repair" made by DNA polymerase
 : -includes other helper proteins - colon cancer islinked to the malfunction of one of these proteins
 : -"excision repair" over 50 enzymes
 : -in the event of an error, dna polymerase and dna ligase catalyze the filling in
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