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What macromolecule carries genetic information?

What macromolecule carries genetic information?. Agenda for Wednesday April 25 th Test stuff Intro DNA notes Create DNA. Timeline of Identifying Genetic Material. Genetic Material Transforms Bacteria - Frederick Griffith, 1931

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What macromolecule carries genetic information?

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  1. What macromolecule carries genetic information? Agenda for Wednesday April 25th • Test stuff • Intro DNA notes • Create DNA

  2. Timeline of Identifying Genetic Material • Genetic Material Transforms Bacteria - Frederick Griffith, 1931 • DNA is the hereditary material - Oswald Avery, Colin MacLeod, and Maclyn McCarty, 1944 • The Genetic Material is DNA - Alfred D. Hershey and Martha Chase, 1952 • Erwin Chargaff, 1940’s and early 50's • M.H.F. Wilkins and Rosalind Franklin, early 50’s • James Watson and Francis H.C. Crick, 1953

  3. Discovery of DNA Griffith • 2 strains of bacteria • Smooth (pneumonia) • Rough (no pneumonia) • Conclusion • Disease was passed • One strain was transformed into the other

  4. Discovery of DNA Avery • Isolated macromolecules from killed S cells • DNA, protein, lipids • Found that living R cells exposed to S strain DNA turned into S cells • Conclusion • DNA released • R strain incorporated this DNA into its cells

  5. Discovery of DNA Hershey and Chase • Bacteriophages – virus that attacks bacteria • Labeled DNA and protein • Radioactive isotopes • DNA – labeled phosphorous • Proteins – labeled sulfur • Conclusion • Viruses must inject DNA into living cell • DNA provided info needed to produce new viruses

  6. DNA - Deoxyribose nucleic acid • Store and transmit genetic information • Composed of smaller nucleotides • DNA is an ideal genetic material • store information • able to replicate • undergo changes (mutate)

  7. Structure of DNA Nucleotides – 3 parts • Deoxyribose sugar • Phosphate group • Nitrogenous base • A, T, C, G

  8. Nitrogenous Bases • 4 Bases • Adenine (A), Thymine (T), Cytosine (C), Guanine (G) • Purine – Double ring • A and G • Pyrimidine – single ring • T and C

  9. Chargaff’s Rule • Found amount of guanine equals amount of cytosine • Amount of adenine nearly equals thyamine • Chargaff’s rule: C=G A=T

  10. Discovering Structure of DNA X – Ray Diffraction • Maurice Wilkins and Rosalind Franklin • Photo 51 • Indicated DNA was a double helix • http://www.pbs.org/wgbh/nova/photo51/

  11. Describe a nucleotide and its parts. Agenda for Thursday April 26th • DNA Extraction Lab • Finish Notes

  12. James Watson and Francis Crick Double Helix Model • Used Franklin’s Photo and Chargaff’s data Features of Model **Similar to ladder that is twisted** 1. Sides formed by sugar-phosphate backbone 2. rungs (or steps) formed by hydrogen bonding between bases of nucleotides 3. bases display complimentary base pairing -- purine always bond to a pyrimidine • A always bonds with T and G always bonds with C

  13. DNA is Complementary • Complementary: bases on one strand match up with the bases on the other strand • (A-T and G-C) Example: Strand 1- ATG GGC CTA Strand 2- TAC CCG GAT

  14. Orientation of DNA • The nucleotides form a chain • The phosphate end of the chain is referred to as the 5' end. The opposite end is the 3' end. • Q: Since DNA is complementary, what end matches with the 5’ end?

  15. Remember DNA is like an Oreo Phophates + sugars = cookies Bases = cream filling Final Thoughts:DNA • Similar to a ladder • Rails (outside of ladder) are deoxyribose and phosphate • Base pairs are rungs of ladder • Twisted

  16. Chromosome Structure • Prokaryotes – DNA in the shape of a ring • Eukaryotic – chromosomes • 51 – 245 million base pairs

  17. Chromosome Structure Chromatin Fibers • DNA wraps around histones • 8 histones form nucleosome Histones Nucleosomes

  18. Remember!! • 2 strands allow bases to pair • A binds T with 2 H bonds • C binds G with 3 H bonds Phosphates + sugars on the outside Bases on the inside (Bases fit like puzzle pieces)

  19. Info on Bases • Purine – double ring base • Guanine, Adenine • Pyrimidine – single ring base • Cytosine, Thymine

  20. What is a nucleotide made of (3 parts)? Agenda for Wednesday May 4th • Create DNA

  21. What shape is DNA? How was this discovered? Agenda for Thursday May 5th • Finish Making DNA • DNA Extraction lab

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