WSC Biotech 2012


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WSC Biotech 2012

  1. 1. WSC: ScienceResource
  2. 2. IntroductionCloning is no longer a thing of the pastBiotechnology transforms us and our perspectiveof the worldBiotechnology can inspire great controversyBioethics: ethics of biological and medicalresearch(researching for answers to questionsasked)
  3. 3. Biotechnology in the pastFocused on fundamental issues: food &beveragesYeast: used by Egyptians to “leaven” bread &used by Sumerians and Babylonians for beerDomestication: the start of biotechnology in away. Animals were selectively breed, steadilyshaped to fit people’s needs(like today’stechnology)
  4. 4. Biotechnology in the pastIn ancient China, moldy soybean curds(anti-botic) were used to treat boilsLancing(slice open) the boil was more popular inancient Rome and in the WestIn Year 0, Chinese farmers discoveredinsecticide
  5. 5. Biotechnology and diseasesSmallpox: one of deadliest disease which killed millionsand had few effective treatmentsVariolation: deliberately exposing someone uninfected to aweakened smallpox virus to create immunity(dated back to11th century)Vaccine was created when Edward Jenner injected fluidfrom a cowpox pustule into his gardener’s eight-year oldson(vaccination)Vaccinations are not 100% effective as diseases canmutate to resist vaccination(nonstable pathogens)HIV: nonstable pathogens with very few vaccinations andtreatment
  6. 6. Biotechnology, Ketchup and Botox + PenicillinPasteurisation: heating of food long enough to killmost bacteria and then cooling for preserving itsflavourStarted by Louis Pasteur, who wanted to preventthe souring of wine and beerBotox: Poison paralysing toxin from bacteria totreat wrinkles, sweaty armpits etcPenicillin: discovered accidentally whenAlexander Felming left bacteria growing in petridishes
  7. 7. Biotechnology and DNAStructure: strands of DNA forms double helix,connected by nucleic acids/bases/necleotidesBase pair: adenine+thymine, guanine+cytosineGenes are combinations of3 nucleotides, chromosomes arelonger chainsProteins as building materialsProduced in ribosomes
  8. 8. Transcription & Translation Forming a protein 1. Gene transcribed 2. Translated into amino acids Exons(coding genes) form only 2% of genes Junk DNA Alleles: dominant and recessive traits Homozygous(homo – same) heterozygous Punnett Square
  9. 9. Genes: MutationMutation: unplanned changes in genesMutagenic factors: radiation, chemicals in environmentRecombinant DNA technology: transferring geneticmaterial through transformation(eg, gene gun)Result: transgenic organismsMutation: use of restriction endonucleases(enzymes) andphageRestriction endonucleases: selecting and cutting of specificpoints, ligase to combine the two ends backtogether(scissors+glue)Phages: construct viruses to carry DNA from one cell toanother(transduction), may cause insertional mutation
  10. 10. Insulin, MALEINFERIORITYYYYYYYY :D level Hormone that regulates sugarAnimal(pancreatic glands of pigs and cows),human(bacteria) and plant(safflower) insulinX(smaller, carries few genes) and Y chromosomeOther X chromosome can backup should the firstX chromosome be defective, Y chromosomecannot backup
  11. 11. Modifications of bodyOrgan transplant: 1st successful from Ronald Herrick toRichard Herrick(twins)Immune system treat them as foreign bodies and rejects,thus the need for immunosuppressant drugsDisadvantage: daily consummation of drugs, limit body’sability to fight actual infectionsXenotransplantation: using organs from other speciesArtificial organs: ventricular assist device, Jarvik-7 in 1982,but it causes blood clotsNewer artificial hearts adjust to user’s needsCosmetic surgery: inject artificial “fillers” in cheeks and lipsto make up for lost collagen
  12. 12. Anti-Depressants, Narcolepsy & ADHDMood depends on levels of neurotransmittersLow levels of serotonin linked with depressionSelective serotonin reuptake inhibitors, eg Prozac, help to keepmore serotonin in the brainOxytocin: hormone linked with feelings of affection andloyalty(when women give birth)Narcolepsy: unable to keep one from falling asleep during the day,even when well-restedADHD: Attention deficit hyperactivity disorderModafinil: stimulant(not as effective as Ritalin and Adderall)Ritalin and Adderall: central nervous system stimulants(similar todrugs)Boosts amount of neorutransmitters norepinephrine & dopamine
  13. 13. Stem cellsUndifferentiated, able to become any type of cell(valuableresource)Ability to renew themselves indefinitelyCan be directed to grow into organs for transplantsDisadvantage: prone to mutationsPluripotent stem cells: most useful, able to become anytissue in the bodyMultipotent stem cells: inactive until repairing/replacingdamaged cells, undifferentiated but only within a relatedgroupUnipotent stem cells: differentiated, can only be one cell
  14. 14. ReproductionFertility drugs boost production of ovaIn vitro fertilisation: extracted eggs are fertilisedoutside female body with sperm beforeimplanting developing embryos into uterusPreimplantation genetic diagnosis(PGD) toassess risk of genetic diseases and traits
  15. 15. Prosthetics & CancerReattached limbs rarely regain all functionsResearchers developing ways to tie prosthetics tobody’s nerves, control artificial limb through thoughtsScientists researching blastema from salamanders, aclump of cells which contain a protein, EV15, whichstops cells from reproducing until they candifferentiateMost cancer treatments take out both good and badcells(eg, hurting hair follicles)Cancer cells present themselves as parts of the body,antigens(foreign substances) are accepted as self-antigens
  16. 16. Vaccines and antiviralsAsian pop. Lack enzyme aldehyde dehydrogenase whichhelps body to break down alcohol(causes drinker to sufferhangover while drinking)Antibodies from vaccines bind to drug molecules, makingthem too large to cross blood-brain barrier, thus usercannot be highAntiviral drugs interfere with viruses’ development,targetting virus-associated proteins(VAPs)Either mimic proteins and bind to receptors, or vice-versaOr interfere with viral synthesis by developinganalogues(compounds with similar molecular structures)that look like pieces of viral genetic materialOr synthesize interferons, the body’s natural defenseagainst viruses(travelling from infected cells and producingproteins to inhibit growth of virus)
  17. 17. Oops, I forgot, mighty mice, genesaCaMKII, memory-erasing proteinMyostatin: inhibits muscle growth by binding tospecial receptors on muscle cellsFollistatin: binds to myostatin and stops it fromactingMore follistatin=more musclesGene therapy for single mutated gene diseases
  18. 18. Cloning Twins show effects of epigenetic changes(physical differences in expression of genes), eg environment of mother’s womb Telomeres sit at end of DNA strands to hold it together Cells divide=telomeres shrink As humans age, telomeres shrink anddamage genetic material• Cancerous cells produce telomeraseWhich lengthens telomeres and prevent cellsFrom dying
  19. 19. Some termsHuamn Growth Hormone(HGH): hormone thatregulates growhtAmphetamines: drugs that speed up body’s andbrain’s response timeOxycontin: powerful painkillersDrugs have severe side effects: steroids weakenheart, amphetamines raise blood pressureNutraceuticals: food products which claim to improvehealth
  20. 20. GMOsGenetically modified organisms(GMOs) were first used toimprove growing of crops, eg soybeansSoybeans vulnerable to weeds, traditional herbicides not veryeffectiveIn 1970, glyphosate(used in herbicide RoundUp) wasdiscoveredIt competes with and inhibits a key enzyme in growing plants,prevents binding to normal amino acid pathway and thus noproteins=plants dieLimited to specific applicationsGenes modified to make certain crops glyphosate resistant byexposing huge amounts of e.coli bacteria to RoundUp inbioreactor(make e.coli bateria resistant to glyphosate)Transgene inserted into crops for resistence
  21. 21. Pesticide, Flavr Savr and SALMON<3Bt-toxin inserted into potato, corn and cottonplants(transgenic) Flavr Savr tomatos: genetically enhanced skinthat soften slowly=long shelf life, but not firmerAquaAdvantage Salmon: modified with gene thatmakes it grow 2x faster than normal salmonMay lead to loss of generic diversity
  22. 22. Biofortified foodsBiofortification: engineering simple and inexpensive foodsto be more nutritiousEg, rice, peanut pasteGolden rice: rice that produces edible beta-carotene(vitamin A) 20x more(gene found in maize)Reduce generic diversityPlumpy’nut: sweet peanut paste with protein, vitamins andminerals(500 calories)No water, no preparation, shelf life=2 yearsMade with vegetable oil which shielded nutrients fromoxygen and humidity and flavourExpensive( 1month=60USD)
  23. 23. BiotechnologyCompare DNA of suspects using variablenumber tandem repeat(VNTR): short pieces ofnoncoding DNA that repeat in a given genome,unique for every individualDNA fingerprinting: high success rate and lowfalse-positive rateCSI NY <3 
  24. 24. Biological Welfare(ohmy:o)Mailed letters infected with bacteria anthrax to governmentofficials(2001)Little vaccine at that time, anthrax=rareOnly a small number of pathogens can wipe out an entire populationFactor of deadliness: incubation periodAnthrax, botulism, plague, smallpox, tularemia, viral hemorrhagicfevers, eg EbolaSmall pox=highly infectious, can cause global pandemic withinternational air travelBiological welfare targets: humans and food(food shortages candestabilise a society, making it vulnerable for defeat)Eg, Agent Orange, deadly herbicide during Vietname War whichdestroyed enemy crops and forest cover, killed 0.5 million, caused birthdefects
  25. 25. MINIATURE FRONTIER(nano) Nanoscale: working with matter so tiny that they cannot be seen with an ordinary microscope Hair: 100 000 nanometers thick Nanobots: diameter of 100 nanometers Nanowires and carbon nanotubes: used in SUPER SUPER tiny circuits for building of tiny robots, sensors, etc Nanobots expected to perform miracles, supposedly killing cancerous cells, unclog arteries,perform surgery, treat diabetes Eg, Nanobots with real DNA, folded into an openbarrel shape(modeled after white blood cells)
  26. 26. Beating Nanowire and uhhum, nanobriefsHeart attack=heart tissue dies , transplanted ornewly grown tissue would not know how to beat inrhythmSolution 1. inject stem cells into damaged regions,coax them to grow heart tissues that responds likeorginalSolution 2. nanopatches with gold nanowires that areplaced over damaged portions of heart.Nanowires(alginate) conduct electricity. New tissuegrown around the nanopatches can respond toelectrical signalsNanobriefs: underwear with sensors to analyse forbody changes and abnormalites
  27. 27. Nanobiotics Nanobots: made of diamond or DNA, can be very precise to search and destroy/repair selected cells Nanoparticles: tiny biodegradable particles that locate target bacteria and attract antibiotics Drill entrances through bacterial cell membranes, attracting and assisting antibotics(defense against antibotics depend on developing hard-to-penetrate cell membranes) Carbon nanotube circuit: sth likesynapse in human brain(junction betweenneurons)o Nano-electrodes coated with membrane thatacts like receptor protein(glutamate) to helpcontrol brain activity