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8. Commonality

8. Commonality

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8. Commonality

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  1. 8. Commonality II. Organism From Viruses to Genetic Engineering

  2. 1918 Spanish Flu

  3. Photo Credit: Cynthia Goldsmith Influenza Virus • RNA Virus • 8 RNA pieces • Spanish Flu epidemic 1918 – 1920: 20 -100 million deaths worldwide • Asian flu 1957-1958: 1- 4 million deaths worldwide • United States: 20,000 deaths annually (National Institute of Allergy & Infectious Disease)

  4. Chicken pox Phage HIV Virus Life? Virus Complex Organized Utilize energy Growth Reproduce Evolve Yes Yes No: lack ability to utilize energy Yes No: must use living cell Yes Non-living particle

  5. Virus

  6. Recognizing Invaders • Antigens: proteins that your body recognizes as foreign (surface) • Two primary antigens in flu virus: • Hemagglutinin (H) • Attachment • Neuraminidase (N) • Release and penetration • Antibodies: proteins produced by your immune system to destroy antigens

  7. How do they do it?Antigenic Drift

  8. Antigenic Drift Mutation Genetic change (random mistakes in copying) Minor annual changes in antigens Flu: H antigen N antigen Flu shots: only effective for predicted strains

  9. Antigenic Shift

  10. Antigen Shift Gene mixing and recombination Species specificity Human Swine Avian (Avian Flu H5 N1) • Strain that can • be capable of infecting humans (bird strain cannot) • become airborne (bird strain is not)

  11. Bird Flu?

  12. Bird Flu? Birds: virus infects gut, transmitted in contact with feces Human: virus infect upper respiratory system, transmitted through cough To be of human concern bird flu needs to acquire the ability to infect respiratory system (airborne) Spanish Flu: mutation allowed this to happen Asian flu H2N2 and Hong Kong flu H3N2 : pigs were infected by human and bird flu, allowed for mixing of genes

  13. Bird Flu: The future

  14. http://www.accessexcellence.org/RC/VL/GG/images/dna2.gif DNA Watson and Crick (Double helix) 1953 (1962 Nobel Prize) Nucleotides Phosphate + Sugar + Base • Bases • A = Adenine • T = Thymine • G = Guanine • C = Cytosine • G & C • A & T combos

  15. Watson and the Structure of DNA

  16. DNA Structure and Function

  17. Making copies How does the information (DNA) get used? Transcription DNA  RNA Translation RNA  Protein

  18. Transcription

  19. Transcription DNA  RNA Intermediate step before proteins are made 3 types of RNA created from genes on DNA Messenger RNA (mRNA) Ribosomal RNA (rRNA) Transfer RNA (tRNA)

  20. Translation

  21. Translation RNA male proteins rRNA: make Ribosomes, carry out translation mRNA: carry the copy of the DNA out of the nucleus tRNA: amino Acid carriers, used to make proteins

  22. Enzymes Proteins that affect biochemical functions Herbert Boyer and Stanley Cohen, 1973 Restriction enzymes Gene splicing: one organism to another

  23. Genetic Engineering

  24. Genetic Engineering Identification and Treatment of disease Gene therapy: use a virus to insert a gene that is defective (Cystic Fibrosis) Synthesize drug: Insulin Patenting of organisms Genetically modified organisms (GMO) Plants (higher yield, resist insects) Animals (spider silk in goat’s milk, BioSteel®)

  25. GM Plants

  26. Public Debate of GM Crops

  27. Genetic Engineering Foods dangerous? Contain genes that are undisclosed or whose function is not fully understood Hazardous to environment? Effects on ecosystems Reproduction in the field creating new strains Outcompete native species Escape How far to go? Fixing problems vs. Improving Humans?

  28. Summary Commonality of Life Same building blocks (RNA, DNA) Same genetic code Same biosynthetic processes Same enzymes Allows for genetic modifications

  29. Next time: ComplexityRead sections:pg 231 4.2, 4.3, 4.7 15.2 16.2, 16.3 pg. 575