1 / 17

Ch. 16 DNA

Ch. 16 DNA. DNA: the Central Dogma, history, structure Replication. History: timeline, people and their accomplishments. Mendel (heredity) Sutton Chromosomes Thomas Hunt Morgan (flies, linkage) Griffith (1928) transformation and mice Avery and colleagues (1944):

mio
Download Presentation

Ch. 16 DNA

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. Ch. 16DNA DNA: the Central Dogma, history, structure Replication

  2. History: timeline, people and their accomplishments • Mendel (heredity) • Sutton Chromosomes • Thomas Hunt Morgan (flies, linkage) • Griffith (1928) transformation and mice • Avery and colleagues (1944): • proposed DNA as the transforming agent • Chargaff (late 40’s-early 50’s) • base pairing (AT CG) • Hershey-Chase (1952) DNA IS hereditary material • Watson and Crick (1953) (Franklin) chemical structure of DNA • Meselson-Stahl mid 1950’s • DNA Replication details

  3. Griffith: Transformation

  4. Hershey / Chase (the hereditary material is not a protein) Radio-active P and S

  5. Whose rule? A-T C-G Purine? Pyrimidine?You have 6 billion pair in every cell!

  6. Chargaff’s Rule • Purines (A, G, double rings) always pair with Pyrimidines (T, C, single rings) • A-T, C-G (& in RNA? ____) • Old AP test question: if in a cell the DNA bases are 17% A’s then what are the %’s of the other bases? • CUT your PY or Pure Silver (Ag)

  7. DNA Replication:SEMICONSERVATIVE MODEL How did they (Meselson-Stahl) prove this? FIG 16.8

  8. KNOW: Steps of ReplicationEnzymesLeading and Lagging strands Okazaki FragmentsAnti-parallel Video

  9. “Bubbles” Replication forks, simultaneous replication **Eukaryotes - multiple origins of replication **Prokaryotes have one Semi-conservative This process is fueled by…nucleoside triphosphates

  10. DNA is made from 5’ to 3’ and it is read from 3’-5’. The 3’ end is the end which elongates (grows) Why is this direction important to consider in Replication?

  11. What do the terms 5’ and 3’ mean?

  12. Leading & Lagging strands, made 5’-3’ Okazaki fragments (are of the lagging strand) ENZYMES: helicase, DNA Polymerase, ligase

  13. Enzymes : • Helicase • •Single strand binding proteins•Primase(RNA Primer)•DNA Polymerase•Ligase • •Nuclease and DNA Polymerase (both are repair enzymes)

  14. Let’s see this in Action • Leading Strand (Nobelprize.org) • Lagging Strand (Nobelprize.org) • Overall (wiley) • Overall 3D view (wehi.edu.au or dnai.org) (Youtube has a music version)

  15. Telomeres Unfilled gap left at the ends of the DNA strands due to the use of RNA primersEventual shortening of DNA over time

  16. Enzyme: Telomerase extends the (3’) long strand so the 5’ strand can finish. Telomerase is found in germ cells that give rise to gametes.

  17. How’s it all fit? • DNA coiling – Let’s see it! DNA from a single skin cell, if straightened out, would be about six feet long but invisible. Half a gram of DNA, uncoiled, would stretch to the sun. Again, you couldn't see it.

More Related