{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

30_DNA_Repair (3)

30_DNA_Repair (3) - DNA Repair Image...

Info icon This preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
DNA Repair Image: http://www.wsu.edu/~smerdon/
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Review of Last Lecture: Mutagenesis Mutations are the source of genetic diversity, but usually have a negative impact on gene function. Mutations can arise spontaneously , or by exposure to a mutagen Point mutations can be caused by rare nucleotide tautomers, direct damage to bases (cytosine deamination, oxidation, or an abasic site), or by insertion of a base analog. Insertions and Deletions can be caused by Intercalating Agents Many human diseases are caused by triplet repeat expansions . These can be caused by strand slippage during replication. Exposure to UV light can cause covalent linkages between adjacent T nucleotides on the same strand (Thymidine dimers)
Image of page 2
DNA Repair Mechanisms I. Direct repair I. Pre-replication mechanisms Nucleotide Excision Repair Bypass polymerase Base Excision Repair Cell-cycle checkpoints and apoptosis III. Post-replication mechanisms Mismatch repair Double-strand break repair IV. DSB repair in non-dividing cells
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Pre-replication vs Post-replication repair: Mutations are NOT “fixed” until replication
Image of page 4
DNA Repair Mechanisms I. Direct repair I. Pre-replication mechanisms Nucleotide Excision Repair Bypass polymerase Base Excision Repair Cell-cycle checkpoints and apoptosis III. Post-replication mechanisms Mismatch repair Double-strand break repair IV. DSB repair in non-dividing cells
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Direct repair: Photolyase uses light energy to repair UV damage Fig 15-22
Image of page 6
DNA Repair Mechanisms I. Direct repair I. Pre-replication mechanisms Nucleotide Excision Repair Bypass polymerase Base Excision Repair Cell-cycle checkpoints and apoptosis III. Post-replication mechanisms Mismatch repair Double-strand break repair IV. DSB repair in non-dividing cells
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
  recognize damage   unwind to make bubble   nick 5’ and 3’ remove damaged fragment Resynthesize (DNA Pol I) and 
Image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern