WSC: Science Resource

Introduction

Cloning is no longer a thing of the past

Biotechnology transforms us and our perspective of the world

Biotechnology can inspire great controversy

Bioethics: ethics of biological and medical research(researching for answers to questions asked)

Biotechnology in the past

Focused on fundamental issues: food & beverages

Yeast: used by Egyptians to “leaven” bread & used by Sumerians and Babylonians for beer

Domestication: the start of biotechnology in a way. Animals were selectively breed, steadily shaped to fit people’s needs(like today’s technology)

Biotechnology in the past

In ancient China, moldy soybean curds(anti-botic) were used to treat boils

Lancing(slice open) the boil was more popular in ancient Rome and in the West

In Year 0, Chinese farmers discovered insecticide

Biotechnology and diseases

Smallpox: one of deadliest disease which killed millions and had few effective treatments

Variolation: deliberately exposing someone uninfected to a weakened smallpox virus to create immunity(dated back to 11th century)

Vaccine was created when Edward Jenner injected fluid from a cowpox pustule into his gardener’s eight-year old son(vaccination)

Vaccinations are not 100% effective as diseases can mutate to resist vaccination(nonstable pathogens)

HIV: nonstable pathogens with very few vaccinations and treatment

Biotechnology, Ketchup and Botox + PenicillinPasteurisation: heating of food long enough to kill most bacteria and then cooling for preserving its flavour

Started by Louis Pasteur, who wanted to prevent the souring of wine and beer

Botox: Poison paralysing toxin from bacteria to treat wrinkles, sweaty armpits etc

Penicillin: discovered accidentally when Alexander Felming left bacteria growing in petri dishes

Biotechnology and DNA

Structure: strands of DNA forms double helix, connected by nucleic acids/bases/necleotides

Base pair: adenine+thymine, guanine+cytosine

Genes are combinations of 3 nucleotides, chromosomes are longer chains

Proteins as building materials

Produced in ribosomes

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

Genes: MutationMutation: unplanned changes in genes

Mutagenic factors: radiation, chemicals in environment

Recombinant DNA technology: transferring genetic material through transformation(eg, gene gun)

Result: transgenic organisms

Mutation: use of restriction endonucleases(enzymes) and phage

Restriction endonucleases: selecting and cutting of specific points, ligase to combine the two ends back together(scissors+glue)

Phages: construct viruses to carry DNA from one cell to another(transduction), may cause insertional mutation

Insulin, MALE INFERIORITYYYYYYYY :D

Hormone that regulates sugar level

Animal(pancreatic glands of pigs and cows), human(bacteria) and plant(safflower) insulin

X(smaller, carries few genes) and Y chromosome

Other X chromosome can backup should the first X chromosome be defective, Y chromosome cannot backup

Modifications of bodyOrgan transplant: 1st successful from Ronald Herrick to Richard Herrick(twins)

Immune system treat them as foreign bodies and rejects, thus the need for immunosuppressant drugs

Disadvantage: daily consummation of drugs, limit body’s ability to fight actual infections

Xenotransplantation: using organs from other species

Artificial organs: ventricular assist device, Jarvik-7 in 1982, but it causes blood clots

Newer artificial hearts adjust to user’s needs

Cosmetic surgery: inject artificial “fillers” in cheeks and lips to make up for lost collagen

Anti-Depressants, Narcolepsy & ADHD

Mood depends on levels of neurotransmitters

Low levels of serotonin linked with depression

Selective serotonin reuptake inhibitors, eg Prozac, help to keep more serotonin in the brain

Oxytocin: hormone linked with feelings of affection and loyalty(when women give birth)

Narcolepsy: unable to keep one from falling asleep during the day, even when well-rested

ADHD: Attention deficit hyperactivity disorder

Modafinil: stimulant(not as effective as Ritalin and Adderall)

Ritalin and Adderall: central nervous system stimulants(similar to drugs)

Boosts amount of neorutransmitters norepinephrine & dopamine

Stem cellsUndifferentiated, able to become any type of cell(valuable resource)

Ability to renew themselves indefinitely

Can be directed to grow into organs for transplants

Disadvantage: prone to mutations

Pluripotent stem cells: most useful, able to become any tissue in the body

Multipotent stem cells: inactive until repairing/replacing damaged cells, undifferentiated but only within a related group

Unipotent stem cells: differentiated, can only be one cell

Reproduction

Fertility drugs boost production of ova

In vitro fertilisation: extracted eggs are fertilised outside female body with sperm before implanting developing embryos into uterus

Preimplantation genetic diagnosis(PGD) to assess risk of genetic diseases and traits

Prosthetics & Cancer

Reattached limbs rarely regain all functions

Researchers developing ways to tie prosthetics to body’s nerves, control artificial limb through thoughts

Scientists researching blastema from salamanders, a clump of cells which contain a protein, EV15, which stops cells from reproducing until they can differentiate

Most cancer treatments take out both good and bad cells(eg, hurting hair follicles)

Cancer cells present themselves as parts of the body, antigens(foreign substances) are accepted as self-antigens

Vaccines and antiviralsAsian pop. Lack enzyme aldehyde dehydrogenase which helps body to break down alcohol(causes drinker to suffer hangover while drinking)

Antibodies from vaccines bind to drug molecules, making them too large to cross blood-brain barrier, thus user cannot be high

Antiviral drugs interfere with viruses’ development, targetting virus-associated proteins(VAPs)

Either mimic proteins and bind to receptors, or vice-versa

Or interfere with viral synthesis by developing analogues(compounds with similar molecular structures) that look like pieces of viral genetic material

Or synthesize interferons, the body’s natural defense against viruses(travelling from infected cells and producing proteins to inhibit growth of virus)

Oops, I forgot, mighty mice, genes

aCaMKII, memory-erasing protein

Myostatin: inhibits muscle growth by binding to special receptors on muscle cells

Follistatin: binds to myostatin and stops it from acting

More follistatin=more muscles

Gene therapy for single mutated gene diseases

CloningTwins 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 and

damage genetic material

• Cancerous cells produce telomerase

Which lengthens telomeres and prevent cells

From dying

Some terms

Huamn Growth Hormone(HGH): hormone that regulates growht

Amphetamines: drugs that speed up body’s and brain’s response time

Oxycontin: powerful painkillers

Drugs have severe side effects: steroids weaken heart, amphetamines raise blood pressure

Nutraceuticals: food products which claim to improve health

GMOsGenetically modified organisms(GMOs) were first used to improve growing of crops, eg soybeans

Soybeans vulnerable to weeds, traditional herbicides not very effective

In 1970, glyphosate(used in herbicide RoundUp) was discovered

It competes with and inhibits a key enzyme in growing plants, prevents binding to normal amino acid pathway and thus no proteins=plants die

Limited to specific applications

Genes modified to make certain crops glyphosate resistant by exposing huge amounts of e.coli bacteria to RoundUp in bioreactor(make e.coli bateria resistant to glyphosate)

Transgene inserted into crops for resistence

Losss of generic diversity

Pesticide, Flavr Savr and SALMON<3

Bt-toxin inserted into potato, corn and cotton plants(transgenic)

Flavr Savr tomatos: genetically enhanced skin that soften slowly=long shelf life, but not firmer

AquaAdvantage Salmon: modified with gene that makes it grow 2x faster than normal salmon

May lead to loss of generic diversity

Biofortified foods

Biofortification: engineering simple and inexpensive foods to be more nutritious

Eg, rice, peanut paste

Golden rice: rice that produces edible beta-carotene(vitamin A) 20x more(gene found in maize)

Reduce generic diversity

Plumpy’nut: sweet peanut paste with protein, vitamins and minerals(500 calories)

No water, no preparation, shelf life=2 years

Made with vegetable oil which shielded nutrients from oxygen and humidity and flavour

Expensive( 1month=60USD)

Biotechnology

Compare DNA of suspects using variable number tandem repeat(VNTR): short pieces of noncoding DNA that repeat in a given genome, unique for every individual

DNA fingerprinting: high success rate and low false-positive rate

CSI NY <3

Biological Welfare(ohmy:o)Mailed letters infected with bacteria anthrax to government

officials(2001)

Little vaccine at that time, anthrax=rare

Only a small number of pathogens can wipe out an entire population

Factor of deadliness: incubation period

Anthrax, botulism, plague, smallpox, tularemia, viral hemorrhagic fevers, eg Ebola

Small pox=highly infectious, can cause global pandemic with international air travel

Biological welfare targets: humans and food(food shortages can destabilise a society, making it vulnerable for defeat)

Eg, Agent Orange, deadly herbicide during Vietname War which destroyed enemy crops and forest cover, killed 0.5 million, caused birth defects

Defense: biosurvelilance, collecting health data and analysing it for abnormalitites

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 open

barrel shape(modeled after white blood cells)

Beating Nanowire and uhhum, nanobriefs

Heart attack=heart tissue dies , transplanted or newly grown tissue would not know how to beat in rhythm

Solution 1. inject stem cells into damaged regions, coax them to grow heart tissues that responds like orginal

Solution 2. nanopatches with gold nanowires that are placed over damaged portions of heart. Nanowires(alginate) conduct electricity. New tissue grown around the nanopatches can respond to electrical signals

Nanobriefs: underwear with sensors to analyse for body changes and abnormalites

Eg, use for soldiers in battle, increase survival rate

NanobioticsNanobots: 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 like

synapse in human brain(junction between

neurons)

o Nano-electrodes coated with membrane that

acts like receptor protein(glutamate) to help

control brain activity

END OF BIOTECH NOTES