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    During replication of DNA, are new complementary nucleotides added to DNA by DNA LIGASE or DNA POLYMERASE?

    Thanks

    BTW I'm doing AQA B Biology.
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    (Original post by buzfvar_1)
    During replication of DNA, are new complementary nucleotides added to DNA by DNA LIGASE or DNA POLYMERASE?

    Thanks

    BTW I'm doing AQA B Biology.
    dna polymerase...dna ligase joins the gaps in the anti-parallel strand.
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    DNA Polymerase
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    polymerase - think polymer (lots of units joined)

    ligase - think ligation (joining together).
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    Aha, so it's both!
    So Ligase zips up the DNA molecule after use whilst Polymerase adds up the new strand, righto?


    Thanks chaps and chapesses
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    ligase joins two ends - in the case of repair this is the newly synthesised DNA and the original part...

    In the case of recombination, at A-Level I would have thought that all you would need to 'apreciate' is that it joins up all the okazaki fragments.
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    DNA polymerase = attracts deoxyribosenucleotides (A,G,T,C) to the original double strand which was unzipped by helicase and binds them there...just like putting it toy blocks to an empty hole which fits its complementary sites

    DNA Ligase = attracts another group of strand single strand(not deoxyribosenucleotides) to form phosphodiester bonds with 2 strands from the 5` direction to 3` direction..its just like connecting 2 railway tracks and using a really strong force to glue them up

    Bear in mind that this is all true if it DNA replication is semi-conservative
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    (Original post by MalaysianDude)
    DNA polymerase = attracts deoxyribosenucleotides (A,G,T,C) to the original double strand which was unzipped by helicase and binds them there...just like putting it toy blocks to an empty hole which fits its complementary sites

    DNA Ligase = attracts another group of strand single strand(not deoxyribosenucleotides) to form phosphodiester bonds with 2 strands from the 5` direction to 3` direction..its just like connecting 2 railway tracks and using a really strong force to glue them up

    Bear in mind that this is all true if it DNA replication is semi-conservative
    If we're going to get technical then polymerase doesn't just catalyse the addition of addition of a deoxynucleoside but also that of nucleoside monophosphate to the 3' oxygen of an existing polynucleotide chain (always acting 5'-3' - a useful mnemonic to remember for all things genetic is N-C, 5-3 - proetiend run from the N-terminal to the C terminal and genes are read fromt he 5' to the 3').

    I would keep it simple - getting cocky in exams without really understanding, or not understanding the whole picture can backfire on you, especially if what you write is only partially true.

    For example, helicase alone does not unwind DNA it requires primase (see T7 for 'case study', also DnaB helicases).
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    Hhhm, oki.
    I'll have a look in the mark scheme for an exam or two to see what they "ask" for in questions dealing with DNA replication.

    Nonetheless, thanks y'all
 
 
 
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