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 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
 DNA replication by Gordon
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DNA replication by Gordon

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Entails information taken from different sources and deals extensively with DNA replication.

Entails information taken from different sources and deals extensively with DNA replication.

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  • Enzymes
    more than a dozen enzymes & other proteins participate in DNA replication
  • The energy rules the process.
  • In 1953, Kornberg was appointed head of the Department of Microbiology in the Washington University School of Medicine in St. Louis. It was here that he isolated DNA polymerase I and showed that life (DNA) can be made in a test tube. In 1959, Kornberg shared the Nobel Prize for Physiology or Medicine with Severo Ochoa — Kornberg for the enzymatic synthesis of DNA, Ochoa for the enzymatic synthesis of RNA.
  • The fifty or so machines needed to translate the DNA code into proteins are made by the DNA code.
    If the machines pre-existed the code there is no way to back translate them into DNA.
    If the machines did not pre-exist the code then they could not be formed even if they existed in the code.
  • Transcript

    • 1. Synthesis Of DNA Presentation By G.H Ngubane 07 March 2014 @ University of Johannesburg AP Biology 2007-2008
    • 2. DNA synthesis occurs by the process of replication. During replication, each of the two parental strands of DNA serves as a template for the synthesis of a Complementary strand. AP Biology
    • 3. Each molecule generated by the replication process contains one intact parental strand and one newly synthesized strand. AP Biology
    • 4. In eukaryotes, DNA replication occurs during the S phase of the cell cycle The cell divides during the next phase (M), and each daughter cell receives an exact copy of the DNA of the parent cells. AP Biology
    • 5. Watson and Crick AP Biology 1953 article in Nature
    • 6. Double helix structure of DNA “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic AP Biology material.” Watson & Crick
    • 7. Directionality of DNA  You need to PO number the carbons!  nucleotide 4 it matters! N base 5′ CH2 This will be IMPORTANT!! 4′ O 3′ AP Biology 1′ ribose OH 2′
    • 8. The DNA backbone  Putting the DNA backbone together  refer to the 3′ and 5′ ends of the DNA  the last trailing carbon Sounds trivial, but… this will be IMPORTANT!! 5′ PO4 5′ CH2 4′ base O 1′ C 3′ O – O P O O 5′ CH2 2′ base O 4′ 1′ 2′ 3′ OH AP Biology 3′
    • 9. Anti-parallel strands  Nucleotides in DNA backbone are bonded from phosphate to sugar between 3′ & 5′ carbons 5′ 3′ 3′ 5′ DNA molecule has “direction”  complementary strand runs in opposite direction  AP Biology
    • 10. Bonding in DNA 5′ hydrogen bonds 3′ covalent phosphodiester bonds 3′ 5′ ….strong or weak bonds? AP Biology the bonds fit the mechanism for copying DNA? How do
    • 11. Base pairing in DNA  Purines adenine (A)  guanine (G)   Pyrimidines thymine (T)  cytosine (C)   Pairing  A:T  2 bonds  AP Biology C:G  3 bonds
    • 12. Copying DNA  Replication of DNA base pairing allows each strand to serve as a template for a new strand  new strand is 1/2 parent template & 1/2 new DNA  AP Biology
    • 13. DNA Replication Let’s meet the team…  Large team of enzymes coordinates replication AP Biology
    • 14. Replication: 1st step  Unwind DNA  helicase enzyme  unwinds part of DNA helix  stabilized by single-stranded binding proteins helicase single-stranded binding proteins AP Biology replication fork
    • 15. Replication: 2nd step  Build daughter DNA strand add new complementary bases  DNA polymerase III  DNA Polymerase III AP Biology But… Where’s the We’re missing ENERGY something! for the bonding! What?
    • 16. Energy of Replication  The nucleotides arrive as nucleosides  DNA bases with P–P–P  P-P-P = energy for bonding   DNA bases arrive with their own energy source for bonding bonded by enzyme: DNA polymerase III ATP AP Biology GTP TTP CTP
    • 17. 5′ Replication  Adding bases  can only add nucleotides to 3′ end of a growing DNA strand  need a “starter” nucleotide to bond to  strand only grows 5′→3′ AP Biology B.Y.O. ENERGY! The energy rules the process 3′ energy DNA Polymerase III energy DNA Polymerase III energy DNA Polymerase III DNA Polymerase III energy 3′ 5′
    • 18. Okazaki Leading & Lagging strands Limits of DNA polymerase III can only build onto 3′ end of an existing DNA strand  ents fragm ki Okaza 3′ 5′ 3′ 5′ 5′ 5′ 3′ ligase growing 3′ replication fork 5′ 5′ Lagging strand Leading strand  3′ Lagging strand   Okazaki fragments joined by ligase AP Biology  “spot welder” enzyme  3′ 5′ 3′ DNA polymerase III Leading strand  continuous synthesis
    • 19. Replication fork / Replication bubble 3′ 5′ 5′ 3′ DNA polymerase III leading strand 5′ 3′ 5′ 3′ 3′ 5′ 5′ 5′ 3′ lagging strand 3′ 5′ 3′ 5′ lagging strand 5′ 5′ leading strand 3′ growing replication fork 3′ leading strand lagging strand 5′ 5′ AP Biology growing replication fork 5′ 5′ 5′ 3′
    • 20. Starting DNA synthesis: RNA primers Limits of DNA polymerase III can only build onto 3′ end of an existing DNA strand  5′ 3′ 3′ 5′ 5′ 3′ 5′ 3′ 5′ growing 3′ replication fork DNA polymerase III primase RNA 5′ RNA primer built by primase  serves as starter sequence AP for DNA polymerase III Biology  3′
    • 21. Replacing RNA primers with DNA DNA polymerase I removes sections of RNA primer and replaces with DNA nucleotides  3′ 5′ DNA polymerase I 5′ 5′ 3′ ligase growing 3′ replication fork RNA 5′ 3′ But DNA polymerase I still can only build onto 3′ end of an Biology AP existing DNA strand
    • 22. DNA polymerases  DNA polymerase III 1000 bases/second!  main DNA builder  Roger Kornberg 2006  DNA polymerase I 20 bases/second  editing, repair & primer removal  DNA polymerase III enzyme AP Biology Arthur Kornberg 1959
    • 23. Editing & proofreading DNA  1000 bases/second = lots of typos!  DNA polymerase I  proofreads & corrects typos  repairs mismatched bases  removes abnormal bases  repairs damage throughout life  AP Biology reduces error rate from 1 in 10,000 to 1 in 100 million bases
    • 24. Fast & accurate!  It takes E. coli <1 hour to copy 5 million base pairs in its single chromosome  divide to form 2 identical daughter cells  Human cell copies its 6 billion bases & divide into daughter cells in only few hours remarkably accurate  only ~1 error per 100 million bases  ~30 errors per cell cycle  AP Biology
    • 25. The importance of nucleotide sequence  The sequence of nucleotides form the unique genetic information of an organism.  The more closely related two organisms are, the more alike the sequence of nucleotides in the DNA will be. Ex: Gel Electrophoresis AP Biology
    • 26. Gel Electrophoresis AP Biology
    • 27. REACTION: o The DNA occurs simultaneously forming sister chromatids. o Nucleotides should always be in pair. o Nucleotides are held together with loose hydrogen bonds. o Every cell in our body has the same copy of DNA, and the DNA will copy itself trillion of times in our lifetime. AP Biology
    • 28. Structure of a nucleotide A nucleotide is made of 3 components:  A Pentose sugar  This is a 5 carbon sugar  The sugar in RNA is ribose.  The sugar in DNA is deoxyribose. AP Biology
    • 29. Structure of a nucleotide  A Phosphate group  Phosphate groups are important because they link the sugar on one nucleotide onto the phosphate of the next nucleotide to make a polynucleotide. AP Biology
    • 30. Structure of a nucleotide  A Nitogenous base  In DNA the four bases are:     Thymine Adenine Cytosine Guanine  In RNA the four bases are:     Uracil Adenine Cytosine Guanine AP Biology
    • 31. AP Biology
    • 32. AP Biology
    • 33. AP Biology
    • 34. Which came first … The letters ? The language ? The transcription machinery ? The storage medium ? The translation machinery ? The transfer medium ? The ATP power plant ? AP Biology
    • 35. Every component used in RNA transcription is made by RNA transcription. RNA Polymerase Ribosomes AP Biology ATP Synthase tRNA Synthase
    • 36. Even if every component is present and in it’s place. Once a cell dies it will not spontaneously revive. It’s order begins to decay. AP Biology
    • 37. The chemicals, components and arrangements necessary for life spontaneously disassemble if the processes of a living cell which maintain order cease to function. AP Biology
    • 38. Acknowledgements 1. Ramesh Mahindrakar 2. RAD DAD GONE MAD Doug Hove 3. MBBS IMS MSU 4. Claudeaa 5. Valerie Evans To view their work click on their names or see links in the reference list. AP Biology
    • 39. Reference List 1.DNA code of life by Ramesh Mahindrakar. Working at G.E. SOCIETY'S J.S.S.COLLEGE GOKAK On Nov 08, 2013 http://www.slideshare.net/RameshMahindrakar/ii-puc-dna?v=qf1&b= from_search=2 2.The DNA Code by RAD DAD GONE MAD Doug Hove. Mechanic Electrian / Fundamental Independent Baptist at Pleasant Valley Baptist Church On Jan 24, 2008 http://www.slideshare.net/CreationCD/the-dna-code?v=qf1&b=&from AP Biology
    • 40. Reference List 3.Bio-Chem synthesis of DNA by MBBS IMS MSU On Jun 21, 2010 http://www.slideshare.net/ananthatiger/biochem-synthesis-of-dna?v from_search=9 4. DNA replication by Claudeaa On Mar 12, 2012 http://www.slideshare.net/claudeaa/dna-replication-11970385? v=default&b=&from_search=2 AP Biology
    • 41. Reference List 5. Chapter 12.2 DNA replication by Valerie Evans On Dec 01, 2011 http://www.slideshare.net/evansv1/chapter-122-dna-replication To view my Slide Share PowerPoint presentation click here slide share PowerPoint Or click on this link http://www.slideshare.net/Gordon-3 AP Biology

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