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8. Commonality. II. Organism. From Viruses to Genetic Engineering. 1918 Spanish Flu. 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
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8. Commonality II. Organism From Viruses to Genetic Engineering
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)
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
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
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
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)
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
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
Making copies How does the information (DNA) get used? Transcription DNA RNA Translation RNA Protein
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)
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
Enzymes Proteins that affect biochemical functions Herbert Boyer and Stanley Cohen, 1973 Restriction enzymes Gene splicing: one organism to another
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®)
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?
Summary Commonality of Life Same building blocks (RNA, DNA) Same genetic code Same biosynthetic processes Same enzymes Allows for genetic modifications
Next time: ComplexityRead sections:pg 231 4.2, 4.3, 4.7 15.2 16.2, 16.3 pg. 575