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18 Cards in this Set
- Front
- Back
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what are the basic features of DNA replication? |
-specific origin -bidirection 5' to 3 ' -semiconservative ( 1 new strand, 1 old strand) -semi-discontinus (leading & lagging strand) |
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Basic requirement of Dna replication.? |
1.) dNTPS (dexoynucleosdie triphosphate) building blocks dGTP etch) 2.) Primers: short strand of nucleotides 3.) template DNA: dsDNA 4.) DNA polymerase:does the replication |
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what is helicases ?
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unwinds, separate 2 strands of DNA -allows binding of primase to make primers |
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what is SSBS? |
single stranded DNA binding protein -stablize ssDNA
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what is topoisomerase? |
removes postive supercoils by DNA unwinding in front of replication fork |
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primase? |
DNA polymerase can't make DNA wi/out a short strand. -RNA polymerase-makes short RNA primers on DNA template |
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replication fork? |
juction btw sepeareted template strand and unreplicated DNA duplex
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what is leading strand? |
continously replicated new strand |
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lagging strand |
new DNA synthesized from other strand |
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okazaki fragment? |
transient intermediates, short fragments of NEW DNA |
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what is DNA polymerase? |
single site to catalyze the addition of dNTPS -monitor base pairing geometry |
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what is the function of DNA polymerase?- |
1.) processivity = fast 2.) proofreading = exonuclease, delete key, removal mismatched |
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what is Rnase H? |
removes RNA primer, degrades hybrid RNA-DNA leaving a gap in the dsDNA |
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what does DNA polymerase do once the RNA primer is removed? |
fills in the gap with DNA except the break in that backbone btw the 3'OH and 5'PO4 |
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what is ligase? |
repairs the "nick" with a phosphodiester bond btw 5"'PO4 and 3"OH |
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what is replication termination? |
events diff. for circular and linear chrome. -type 2 topoiosomerases are required for circular chrom -lagging strand synthesis unable to copy = replication problem |
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what are telomeres? |
ends of euk. chromomsome -T-G rich head to tail repeats end sequences confer stability on molecule |
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what is telomerase? |
adds the telomeric sequence to the 3' OH end of chrom -3' extension ensures that telomeres are maintained sufficiently |
