Finishing DNA Replication : Finishing DNA Replication Problem 1: There are still RNA nucleotides in the DNA (primers)?
Solution = DNA Polymerase I cuts out the RNA nucleotides and replaces them with DNA
Finishing DNA Replication : Finishing DNA Replication Problem 2: Okazaki fragments and bases replaced DNA Polymerase I are not attached to rest of DNA
Solution = DNA Ligase seals everything together
Putting It All Together : Putting It All Together Label the diagram on with the following terms:
SSBs - DNA Ligase
Leading Strand - Lagging Strand
Helicase - Primase
DNA Polymerase III - Primer
DNA Polymerase I
Slide 4 : Helicase
Slide 5 : SSBs DNA
Polymerase III Primase Primer DNA Pol
III Lagging
Strand DNA
Polymerase I Leading Strand DNA Ligase Helicase
Proofreading New DNA : 6 Proofreading New DNA DNA polymerase initially makes about 1 in 10,000 base pairing errors
Enzymes proofread and correct these mistakes
The new error rate for DNA that has been proofread is 1 in 1 billion base pairing errors
DNA Damage & Repair : 7 DNA Damage & Repair Chemicals & ultraviolet radiation damage the DNA in our body cells
Cells must continuously repair DAMAGED DNA
Excision repair occurs when any of over 50 repair enzymes remove damaged parts of DNA
DNA polymerase and DNA ligase replace and bond the new nucleotides together
Question: : 8 Question: What would be the complementary DNA strand for the following DNA sequence?
DNA 5’-CGTATG-3’
Answer: : 9 Answer: DNA 5’-GCGTATG-3’
DNA 3’-CGCATAC-5’
Slide 10 : 10 THANK YOU