DNA Replication
Discovering the structure of DNA   <ul><li>DNA =  D eoxyribose  n ucleic  a cid </li></ul><ul><li>Made out of sugars (deox...
Discovering the structure of DNA   <ul><li>Structure was discovered in 1953 by James  </li></ul><ul><li>Watson and Francis...
Others contributed to the discovery of DNA Rosalind Franklin: DNA image through X-ray technology Erwin Chargaff found that...
Cell division – why DNA replicates! <ul><li>Cells divide </li></ul> Growth, Repair, Replacement <ul><li>Before cells divi...
DNA replication
DNA REPLICATION <ul><li>the process by which DNA makes a copy of itself (cell division) </li></ul>SEMI-CONSERVATIVE - half...
DNA replication
Replication: 1st step <ul><li>Unwind DNA </li></ul><ul><ul><li>helicase  enzyme </li></ul></ul><ul><ul><ul><li>unwinds par...
DNA replication
DNA replication
Replication: 2nd step DNA Polymerase III But … We ’ re missing  something ! What? Where ’ s the ENERGY for the bonding ! <...
Energy of Replication <ul><li>Where does energy for bonding  usually  come from? </li></ul>energy ATP GTP TTP CTP ADP AMP ...
DNA replication
DNA replication Original DNA strands
DNA replication Newly assembled DNA strands
DNA replication Semi-conservative replication
Figure 11.8 Schematic representation of DNA Polymerase III Structure resembles a human right hand Template DNA thread thro...
DNA polymerases <ul><li>DNA polymerase III </li></ul><ul><ul><li>1000 bases/second ! </li></ul></ul><ul><ul><li>main  DNA ...
Editing & proofreading DNA <ul><li>1000 bases/second =  lots of typos! </li></ul><ul><li>DNA polymerase I   </li></ul><ul>...
Replication fork 3’ 5’ 3’ 5’ 5’ 3’ 3’ 5’ helicase SSB = single-stranded binding proteins primase DNA  polymerase III DNA  ...
 
The next part of the process <ul><li>Use a strand of DNA to make RNA </li></ul><ul><li>RNA is then used to make proteins <...
DNA -->  RNA -->  Protein Proteins are the building blocks of the organism (traits)
Transcription  -  process where RNA is made from DNA Translation  - process where proteins are made from RNA
 
Upcoming SlideShare
Loading in …5
×

Dna replication

1,635 views
1,253 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,635
On SlideShare
0
From Embeds
0
Number of Embeds
53
Actions
Shares
0
Downloads
40
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • 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.
  • Dna replication

    1. 1. DNA Replication
    2. 2. Discovering the structure of DNA <ul><li>DNA = D eoxyribose n ucleic a cid </li></ul><ul><li>Made out of sugars (deoxyribose), phosphates </li></ul><ul><li>and nitrogen bases </li></ul>
    3. 3. Discovering the structure of DNA <ul><li>Structure was discovered in 1953 by James </li></ul><ul><li>Watson and Francis Crick </li></ul>
    4. 4. Others contributed to the discovery of DNA Rosalind Franklin: DNA image through X-ray technology Erwin Chargaff found that number of bases were approximately equal to their bonding partner A = T & C = G
    5. 5. Cell division – why DNA replicates! <ul><li>Cells divide </li></ul> Growth, Repair, Replacement <ul><li>Before cells divide they have to double cell </li></ul><ul><li>structures, organelles and their genetic </li></ul><ul><li>information </li></ul>
    6. 6. DNA replication
    7. 7. DNA REPLICATION <ul><li>the process by which DNA makes a copy of itself (cell division) </li></ul>SEMI-CONSERVATIVE - half of the old strand is saved
    8. 8. DNA replication
    9. 9. Replication: 1st step <ul><li>Unwind DNA </li></ul><ul><ul><li>helicase enzyme </li></ul></ul><ul><ul><ul><li>unwinds part of DNA helix </li></ul></ul></ul><ul><ul><ul><li>stabilized by single-stranded binding proteins </li></ul></ul></ul>single-stranded binding proteins replication fork helicase
    10. 10. DNA replication
    11. 11. DNA replication
    12. 12. Replication: 2nd step DNA Polymerase III But … We ’ re missing something ! What? Where ’ s the ENERGY for the bonding ! <ul><li>Build daughter DNA strand </li></ul><ul><ul><li>add new complementary bases </li></ul></ul><ul><ul><li>DNA polymerase III </li></ul></ul>
    13. 13. Energy of Replication <ul><li>Where does energy for bonding usually come from? </li></ul>energy ATP GTP TTP CTP ADP AMP GMP TMP CMP modified nucleotide energy We come with our own energy ! And we leave behind a nucleotide ! You remember ATP ! Are there other ways to get energy out of it? Are there other energy nucleotides? You bet !
    14. 14. DNA replication
    15. 15. DNA replication Original DNA strands
    16. 16. DNA replication Newly assembled DNA strands
    17. 17. DNA replication Semi-conservative replication
    18. 18. Figure 11.8 Schematic representation of DNA Polymerase III Structure resembles a human right hand Template DNA thread through the palm; Thumb and fingers wrapped around the DNA
    19. 19. DNA polymerases <ul><li>DNA polymerase III </li></ul><ul><ul><li>1000 bases/second ! </li></ul></ul><ul><ul><li>main DNA builder </li></ul></ul><ul><li>DNA polymerase I </li></ul><ul><ul><li>20 bases/second </li></ul></ul><ul><ul><li>editing, repair & primer removal </li></ul></ul>DNA polymerase III enzyme Arthur Kornberg 1959 Roger Kornberg 2006
    20. 20. Editing & proofreading DNA <ul><li>1000 bases/second = lots of typos! </li></ul><ul><li>DNA polymerase I </li></ul><ul><ul><li>proofreads & corrects typos </li></ul></ul><ul><ul><li>repairs mismatched bases </li></ul></ul><ul><ul><li>removes abnormal bases </li></ul></ul><ul><ul><ul><li>repairs damage throughout life </li></ul></ul></ul><ul><ul><li>reduces error rate from 1 in 10,000 to 1 in 100 million bases </li></ul></ul>
    21. 21. Replication fork 3’ 5’ 3’ 5’ 5’ 3’ 3’ 5’ helicase SSB = single-stranded binding proteins primase DNA polymerase III DNA polymerase III DNA polymerase I ligase Okazaki fragments leading strand lagging strand SSB direction of replication
    22. 23. The next part of the process <ul><li>Use a strand of DNA to make RNA </li></ul><ul><li>RNA is then used to make proteins </li></ul><ul><ul><li>happens at ribosomes </li></ul></ul><ul><ul><li>proteins control everything about the organism </li></ul></ul>
    23. 24. DNA -->  RNA -->  Protein Proteins are the building blocks of the organism (traits)
    24. 25. Transcription -  process where RNA is made from DNA Translation - process where proteins are made from RNA

    ×