1 / 18

DNA REPLICATION AND REPAIR

DNA REPLICATION AND REPAIR. By: Kainat, Pauletta, and Kelin. sugar deoxyribose (5 carbon molecule) 4 nitrogenous bases (stores genetic info) (AT- 3H bonds= stronger) (CG- 2H bonds= weaker) phosphate group bond with sugar deoxyribose to form twin backbones. DNA STRUCTURE:.

parkerjames
Download Presentation

DNA REPLICATION AND REPAIR

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DNA REPLICATION AND REPAIR By: Kainat, Pauletta, and Kelin

  2. sugar deoxyribose (5 carbon molecule) 4 nitrogenous bases (stores genetic info) (AT- 3H bonds= stronger) (CG- 2H bonds= weaker) phosphate group bond with sugar deoxyribose to form twin backbones DNA STRUCTURE:

  3. DNA antiparallel- DNA strands “run” opposite direction (3’ to 5’ prime end) DNA is SEMICONSERVATIVE REPLICATION Semiconservative Replication:Original DNA would split therefore acting like template for new DNA strand DNA DIRECTION

  4. DNA REPLICATION: Making copies of DNA! Eukaryotes: Inside nucleus WHEN: Interphase of cell cycle- in sphase - does not replicate in cell division (mitosis) because DNA should be there already Prokaryotic: Inside the cytoplast WHEN:Binary Fussion DNA REPLICATION

  5. Leading and Lagging Strand ******DNA POLYMERASE ONLY WORKS IN THE 5’-3’ DIRECTION******** Why? because it can only add nucleotides at the 3’ carbon end Lagging strand runs from 3’-5’ direction Leading Strand runs from 5’ to 3’ REQUIRES LESS STEPS

  6. Helicase comes and unwind the DNA SSBP- Single- Stranded Binding Proteins bind to the DNA strand and keep them separated RNA primase- adds an primer( a piece of RNA) DNA polymerase- adds complementary DNA bases lagging strand Repeats 3 and 4 DNA ligase- connects the okazaki Fragments STEPS( leading strand)

  7. 2 identical double helix molecules= SEMICONSERVATIVE REPLICATION -------------->>>>> because one original strand and another new strand END PRODUCT

  8. DNA POLYMERASE rarely makes mistakes because of proofreading SINGLE STRANDED: specialized repair enzymes: mismatch repair- (in bases) enzymes catch error, cut nucleotide and repair. second set protein check: find mismatch, cut, and replace https://www.youtube.com/watch?v=5qSrmeiWsuc https://www.youtube.com/watch?v=JIPw-Bd0WGg https://www.youtube.com/watch?v=vP8-5Bhd2ag DNA REPAIR

  9. base excision repair- one enzyme takes damaged base trims around the site and replace the base specialized repair enzymes:

  10. nucleotide excision repair- UV light ---> 2 adjacent nucleotides stick together distorting double helix shape team of proteins remove long strand of nucleotides and replace specialized repair enzymes:

  11. Can BREAK 1 or 2 strands homologous recombination: uses undamaged section of similar DNA as template, enzymes interlace damaged and undamaged strands to exchange sequences of nucleotides and fill missing gaps non-homologous end joining: (No template strand) proteins trim out few nucleotides and fuse broken ends back together DOUBLE STRANDEDGAMMA AND X-RAYS

  12. IF HAVE 5’ AGGTCCG 3’ 3’ TCCAGGC 5’ DNA REPLICATION DNA REPLICATION DNA REPLICATION TEST YOUR KNOWLEDGE NAME THE FUNCTIONS OF THE FOLLOWING ENZYMES: Helicase: unzipping Primase-Initializer DNA polymerase- builder Ligase-glue define SEMICONSERVATIVE REPLICATION: one original and new strand DNA POLYMERASE ONLY WORKS IN THE 5’-3’ DIRECTION

  13. mismatch repair- (in bases) enzymes catch error, cut nucleotide and repair. base excision repair- enzyme takes damaged base, trims around the site, & replace base nucleotide excision repair- (UV light) 2 adjacent nucleotides stick together distorting double helix shape. Team of proteins remove long strand of nucleotides and replace DOUBLE STRANDED: homologous recombination: undamaged section of DNA= template, enzymes interlace damaged and undamaged strands= exchange sequences of nucleotides and fill missing gaps non-homologous end joining: (No template strand) proteins trim out few nucleotides and . fuse broken ends back together DNA REPAIR TEST YOUR KNOWLEDGE HOW DO THEY WORK? SINGLE STRANDED

  14. DNA Repair. (2015, October 31). Retrieved January 13, 2016, from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/DNArepair.html ED, T. (2015, September 21). What happens when your DNA is damaged? - Monica Menesini. Retrieved January 13, 2016, from https://www.youtube.com/watch?v=vP8-5Bhd2ag Sisters, A. (2014, June 16). DNA Replication: The Cell's Extreme Team Sport. Retrieved January 13, 2016, from https://www.youtube.com/watch?v=5qSrmeiWsuc Google Images What is DNA replication? (2015, March 9). Retrieved January 13, 2016, from http://www.yourgenome.org/facts/what-is-dna-replication BIBLIOGRAPHY

More Related