1. Today’s Outline DNA and DNA Replication Review – Leading Strand vs. Lagging Strand – DNA Pol I vs. DNA Pol III Telomeres Molecular Sculpting – DNA Replication – PCR What’s Due? – StudyNotes 7 is due on Thursday Mar 21 – HW # 5 and is due on Tuesday Mar 26. – StudyNotes 8a is due on Tuesday Mar 26.

2. hydrogen bonds

3. Strand

4. 3’ carbon 5’ carbon

6. A DNA Double Helix has a regular, repeated structure

10. DNA Polymerase III Adds dNTPs to the newly synthesized strand on the leading strand. Adds to the 3’ end of a ribose.

11. DNA Polymerase I DNA Primase creates primers (red) that are RNA molecules. DNA Pol I replaces the RNA nucleotides with DNA nucleotides.

13. Ends of parental DNA strands Leading strand Lagging strand Last fragment Previous fragment Parental strand RNA primer Removal of primers and replacement with DNA where a 3 end is available Second round of replication New leading strand New lagging strand Further rounds of replication Shorter and shorter daughter molecules 5 3 3 3 3 3 5 5 5 5 5 3 DNA Pol1 Can only add nucleotides to the 3’ end of existing DNA. Telomeres protect an organism’s genes from being eroded during successive rounds of DNA replication. In humans the sequence TTAGGG is repeated between 100 and 1000 times.

14. Molecular Sculpting Two Models: 1.DNA Replication – must include: – Helicase, topoisomerase, single strand binding proteins, DNA primase, the sliding clamp, DNA pol I, DNA pol III and ligase. – Okazaki fragments, RNA primers, leading strand, lagging strand, nucleotides and free dNTPs. 2.Polymerase Chain Reaction – must include: – Three panels: denaturing, annealing and extending. – DNA, forward and reverse DNA primers, taq polymerase, dNTPs.