DNA_Structure - addition of new nucleotides one by one The...

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Structure of Nucleic Acids: nucleotide structure nitrogenous bases * purines (a=adenine, g=guanine) (double ring) * pyrimidines (t=thymine, c=cytosine) (single ring) all species the amount of A=T and G=C but each species has its own ratio of AT/GC model of how nucleotides combine to form a polymer Model for DNA structure: Mechanism for replication: PROCESS OF REPLICATION: (eucaryotes) Replication begins at the replication origin (up to 1,000 per DNA molecule) Helicase enzymes SSB proteins (single strand binding proteins) Primase now builds a short RNA primer (~10 nucleotides) 5' to 3' DNA polymerase enzymes now bind to the strand next to the primer and catalyzes the
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Unformatted text preview: addition of new nucleotides, one by one The DNA polymerase move only in one direction that is the new strand will always be built from its 5' to its 3' end. DNA ligase Three questions of interest concerning this process 1. What happens if the wrong base is added to the growing strand? 2. Where does the energy for these reactions come from? 3. Why does DNA polymerase only build the new strand 5' to 3'? DNA Repair there are 50 or more repair enzymes which replace these damaged areas of DNA with the appropriate nucleotides....
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This note was uploaded on 02/14/2011 for the course BIOL 1201 taught by Professor Wishtichusen during the Spring '07 term at LSU.

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