XII Chap 12 Biotechnology Applications Flashcards
Some of the applications of biotechnology?
Therapeutics Diagnostics Genetically modified crops Processed food Bioremediation Waste treatment Energy production
3 critical areas of research in biotech?
- Best catalyst - improved microbe or pure enzyme
- Optimal conditions for a catalyst to act
- Downstream processing technologies to purify protein/organic compound
___________ succeeded in tripling the food supply
Green Revolution
What are agrochemicals?
Fertilisers and pesticides
What are GMO?
Genetically Modified Organisms
Bacteria, Fungi, Plants and Animals whose genes have been altered
How has GM been useful?
- Crops more tolerant to abiotic stresses
- Reduced reliance on chemical pesticides
- Reduced post harvest losses
- Increased efficiency of mineral usage by plants (prevents early exhaustion of soil fertility)
- Enhanced nutritional value of food
What is Bt toxin?
What is a biopesticide?
toxin produced by bacterium Bacillus thuringiensis (Bt)
Plant in which gene has been cloned and to create resistance to insects
Examples of bio-pesticides?
Bt cotton, Bt corn
rice
tomato, potato and soyabean
How does Bt kill insects?
Protein crystals - toxic insecticidal protein.
Inactive in Bt, active in alkaline pH of the insect’s gut
Crystals solubilise => toxin binds to midgut epithelial cells => creates pores => cell swelling and lysis => death
Bt toxins are insect group specific and so choice of gene depends on the crop + targeted pest. T or F?
True
Which gene codes the toxin in Bt?
cryIAc named “cry”
________ and _______ genes control the cotton ballworms
________ gene controls corn borer
cryIAc cryIIAb control the cotton ballworms
cryIAb controls corn borer
_______ infects root of tobacco plants
nematode Meloidegyne incornitia
How has the tobacco plant been made resistant to nematodes?
RNA interference (RNAi)
vector - Agrobacterium
gene produced both sense and anti-sense RNA (complementary) => double-stranded dsRNA => RNAi initiated => silenced nematode mRNA => death
What is RNAi?
RNA interference is a cellular defense mechanism in all eukaryotic organisms
How does RNAi work?
A specific mRNA gets silenced due to a complementary dsRNA molecule that binds to mRNA and prevents translation of mRNA
source of this complementary dsRNA can be viruses or transposons
At present ________ recombinant therapeutics have been approved and _____ are used in India
30; 12
Insulin used for diabetes was previously extracted from _______
pancreas of slaughtered cattle and pigs => some patients had allergies and other reactions
What does insulin consist of ?
Two short polypeptide chains
chain A and chain B
linked - disulphide bridges
How is insulin synthesised in mammals?
Pro-insulin needs to be processed before it becomes mature and functional;
contains an extra stretch of C-peptide => removed during maturation into insulin
How is insulin produced now? Who pioneered it?
Eli Lilly - American company - 1983
two DNA sequences - one for chain A and one for chain B => introduced into plasmids of E coli to produce insulin chains => produced separately, extracted and combined with disulfide bonds => human insulin
What does gene therapy involve?
correction of a genetic defect
delivery of a normal gene into individual/embryo
First clinical gene therapy?
1990, 4-year-old girl, ADA deficiency, crucial enzyme for immune system
usually treated by bone marrow transplant or injection => both are not curative
lymphocytes from patient grown in culture => functional ADA cDNA introduced using retroviral vector => returned to patient.
Patient requires periodic infusion. However, if introduced in embryonic stages could be permanent
What are some techniques for early diagnosis of a disease?
Recombinant DNA technology
Polymerase Chain Reaction (PCR)
Enzyme Linked Immuno-sorbent Assay (ELISA)
Very low concentration of a bacteria or a virus can be detected by a PCR. T or F?
True
______ is now routinely used to detect HIV in suspected AIDs patients and gene mutations in suspected cancer patients
PCR
ELISA is based on what principle?
antigen-antibody interaction;
presence of antigen or antibodies => infection by pathogen
What are transgenic animals?
DNA manipulated to possess/express an extra/foreign gene
Over 95% of transgenic animals are ______
Mice
Why are transgenic animals produced?
- Study gene regulation and effect of genes i.e. normal physiology and development
- Study disease (cancer, cystic fibrosis, rheumatoid arthritis and Alzheimer’s)
- Biological products - in 1997, the first transgenic cow produced human protein-enriched milk
- Vaccine safety - test polio vaccines
- Chemical safety testing - transgenic animals made that are more sensitive to toxic substances, exposed and studied
______ can replace monkeys to test safety batches of vaccines
Transgenic mice
________ varieties of rice in Inida
200,000
What is biopiracy?
Use of bio-resources by multinational companies / other organisation without proper authorisation from countries and people concerned without compensatory payment
Human insulin these days is made in _________
bacteria
_______ are used as vectors in gene therapy
Viruses
