Biotechnology Flashcards
1
Q
What can bacteria be genetically engineered to produce?
A
Valuable products - fuels, chemicals, drugs, human hormones.
2
Q
What are three biotechnological approaches?
A
Use products naturally produced by bacteria, use genetic mod to introduce entire pathway and harvest products, use genetic mod to express single gene and harvest protein produced.
3
Q
How is acetic acid a natural product?
A
Acetic acid bacteria, produce acetic acid from sugars or ethanol, obligate aerobes, grow well at pH<5.
4
Q
How can vitamin C be a natural product of bacteria?
A
Acetic acid bacteria can carry out incomplete oxidation of some higher alcohols and sugars, metabolic products used to make vitamin C.
5
Q
How are antibiotics a natural product of bacteria?
A
Produced by streptomycetes, over 500 distinct produced, some produce more than others.
6
Q
How is Swiss cheese a natural product of bacteria?
A
Propionic acid bacteria, produce CO2 and acid during fermentation, gas build up forms holes, gives characteristic taste.
7
Q
What is one of the most profitable areas of biotechnology?
A
Human protein production - genetic modification of bacteria to produce high yields of desired protein.
8
Q
What was the first human protein to be commercially produced by bacteria?
A
Insulin, on sale in 1982, Humulin.
9
Q
In what way was insulin genetically produced?
A
Via small peptides - efficient to construct artificial gene that encodes final hormone than one large precursor protein for insulin.
10
Q
What must eukaryotic genes be put under the control of?
A
A bacterial promoter.
11
Q
How was the bacterial promoter problem of expressing mammalian genes in bacteria solved?
A
Design special expression vectors with bacterial promoters and ribosome binding site.
12
Q
What is another issue other than needing a bacterial promoter for genetic modification?
A
Bacterial genes don’t have introns, must be removed from eukaryotic gene.
13
Q
How do you remove the introns from a eukaryotic gene?
A
Clone gene via mRNA and cDNA.
14
Q
What is codon bias and why may it be an issue to genetic modification?
A
May require edits to sequence, genetic code degenerate, codon usage varies from organism to organism.
15
Q
How can you overcome codon bias?
A
You may need to alter the codons to fit with those recognised by your bacterial species.
16
Q
What may further engineering of the host or vector solve?
A
Possible degradation of protein in host cell or possible toxicity of euk protein to prokaryotic host.
17
Q
What do you need to produce metabolites rather than proteins?
A
Single gene will not suffice, need to build up whole metabolic pathway - requires multiple genes and regulation/coordination of expression.
18
Q
What is pathway engineering?
A
Process of assembling a new or improved biochemical pathway using genes from one or more organisms.
19
Q
What is the aim of pathway engineering?
A
To produce large amounts of a particular metabolite, mostly focused on improving existing pathways.
20
Q
In what way can the reaction itself be more useful than the product?
A
Microbes can be used to breakdown detrimental compounds - industrial enzymes.
21
Q
What is bioremediation?
A
The microbial clean up of environmental pollutants.
22
Q
What are some examples of pollutants?
A
Oil, radionuclides, pesticides, plastics.
23
Q
How do we solve the plastic problem?
A
Microbial plastics, biodegradable, using bacterial storage polymer.
24
Q
What is the name of the bacterial storage polymer used in making microbial plastics?
A
Polyhydroxyalkanoates (PHAs).
25
What are some issues associated with microbial plastics?
Issues with cost of production vs synthetic plastics and competition with biofuels for carbon substrates.
26
How can we used microorganisms for mining?
Have diverse metabolisms, can be used to extract valuable metals from low grade ores, called microbial leaching.
27
What main biotechnological processes require bacteria as a tool?
Biotech, cloning, DNA manipulation.
28
What is the metagenome?
The collective genomes of all the organisms growing in an environment.
29
What is gene mining?
Isolating potentially useful novel genes without having to first culture the organism.
30
What do the noval genes that metagenomics has identified encode?
Enzymes that degrade pollutants, antibiotics, lipases, chitinases, esterases, enzymes with improved resistance to industrial production conditions.
31
What is targeted gene mining?
Metagenomics can be used to screen directly for enzymes without having certain properties.
32
What is the first step of targeted gene mining?
Need and enzyme capable of degrading a certain pollutant.
33
What is the second step of targeted gene mining?
Find environment polluted with the targeted compound.
34
What is the third step of targeted gene mining?
Isolate and clone DNA from that environment.
35
What is the fourth step of targeted gene mining?
Bacteria containing clones screened for growth on target compound.
36
What is the final step of targeted gene mining?
Cells extracts from potential suspects are tested in vitro for the enzyme of interest.
37
In what ways were fungi at the start of industrial microbiology?
Alcoholic fermentation in 1851, pure strain brewing in 1883, citric acid plant in 1923.
38
Why are fungi microorganisms so good?
Ease of mass cultivation, grow rapidly, on cheap substrates, diversity of potential products, genetically manipulated.
39
What pharmaceuticals are a result of fungi biotechnology?
Antibiotics, steroids, statins, other drugs.
40
What is the story behind penicillin?
Fleming noted effect on bacteria, purified by Florey and Chain in 1941, now a wonder drug.
41
What are steroids useful for?
Arthritis, asthma, eczema, used to be costly to produce.
42
History behind production of cortisone steroid?
Used to be extracted from animal adrenal glands, rhizpous arrhizus converts diosgenin to intermediate then to cortisone, reduced cost.
43
What drug for asthma and nose-drops/inhalants can be produced from yeast species.
1-Ephedrine.
44
What are Ergot alkaloids used for?
Vasoconstrictors, induction of contractions, treatment of migraines, lysergic acid.
45
What do statins do?
Control cholesterol levels.
46
What are some organic acids?
Citric acid, itaconic and gluconic acid, ascrobic acid.
47
What is fermented to form citric acid?
Aspergillus niger.
48
What can citric acid be used for?
Food industry, prevent loss of vitamin C in canned fruit nad vegetables.
49
What is itaconic acids used for and produced from?
Improve properties of vinyl polymers, produced from aspergillus terreus.
50
What is gluconic acid used for and produced from?
Used in toothpaste manufacture, produced by Aspergillus niger.
51
What is an industrial alcohol and how is it used?
Ethanol, solvent, from petroleum or yeast, fermentation attractive pathway.
52
What are glycerols produced from and how are they used?
From Saccharomyces cerevisiae, used as solvents, plasticizers, sweeteners, explosives, soaps, printing.
53
What is a plant growth promoter produced from fungi?
Giberellic acid.
54
How can fungi be used as food?
Mushroom production.
55
What can mycoprotein be used for?
Quorn.
56
What are some uses of fungi in the food industry?
Beverages, bakers yeast, dairy produce, food additives, Asian foods, amino acids.
57
How are bread and beverages produced?
Yeats, strains of Saccharomyces cerevisiae, yeast ferment glucose to yeild ethylene alcohol and carbon dioxide.
58
What Asian foods are fungi used for?
Tempeh, Shoyu (soy sauce).
59
What is biological control?
Can be defined as use of one organism to control another, an attractive alternative to chemical pesticides.
60
Why has microbes success as biological control agents been limited?
Their ability to control a narrow range of pests, by their slow action and short field life.
61
What is bioremediation?
The use of living organisms or their products to metabolise or detoxify environmental pollutants.
62
What has most of fungal bioremediation been centred around?
Lignin-degrading enzyme system of white rot fungi.
63
What is mycofiltration?
The impregnation of fungal spores and hyphae into fabric landscaping cloth, these fabrics are overlaid into contaminated ground and fungal act as filter.
64
Why are plants important?
Food and fodder, textiles/fibres, paper/wood products, biodiversity, ornamentals/amenity, petroleum/substitutes, pharmaceuticals/cosmetics.
65
What is plant biotechnology?
Application of science and technology to plants, parts, products and models, to alter living or inert materials, in order to develop knowledge, goods and services.
66
What are examples of plant biotechnology?
Plant cell factories, tissue culture, transgenic plants, molecular breeding, wine making, food processing, plant breeding.
67
What are micronutrients?
Vitamins and minerals.
68
What are macronutrients?
Water, proteins, carbs, fats.
69
What was the green revolution?
A planned international effort in the 1970s to increase crop yield through new crop cultivars, irrigation, fertilisers, pesticides, mechanisation.
70
What were the outcomes of the green revolution?
Reduced chronic hunger from 40% to 20% of world population while pop doubled, saved millions of hectares of land from cultivation.
71
How many people are still undernourished?
800 million people.
72
What did the green revolution achieve?
Faster growth, high yeild, semi dwarf habit, disease resistance, adaptability to local conditions.
73
How did the green revolution create faster growth?
More than one crop cycle per year.
74
What was the semi dwarf habit?
Created strong stems that don’t fall over (lodging).
75
How did the green revolution achieve higher yeild?
Better soil assimilation and better biomass.
76
What were examples of diseases resistance produced from the green revolution?
Wheat rust and rice blast.
77
What was an example of adapting to local conditions during the green revolution?
First ‘miracle rice’ IR8.
78
What does plant tissue culture refer to?
Many plants can regenerate from cutting from a few cells but only if the right hormones are provided.
79
What is an example of useful plant tissue culture using meristems and sterile cultures?
Micropropagation.
80
How does the useful example of plant tissue culture, elimination of systemic viruses, work?
The virus infects the plant but can’t infect the meristem, sterile culture of meristem eliminates virus, creates healthy crop.
81
What is an example of molecular breeding?
Fruit tree breeding.
82
How is molecular breeding undertaken?
Find a DNA marker that is closely linked to fruit character, follow it in progeny of a cross, use the marker to identify seedlings that will bear red fruit.
83
What are SNPs?
Single nucleotide polymorphisms.
84
How do we find markers for molecular breeding?
Generate fingerprint of parent plant using random markers (SNPs), find markers linked to phenotypes, check linkage is close, use markers to identify plants at seedling.
85
What is protoplast fusion and what is it used for?
Tool for creating wide crosses between similar but different species - speeds up plant breeding.
86
What are the steps of protoplast fusion?
Treat plant tissue with enzymes to remove cell walls, creates protoplast, fuse from different genotypes, use polyethylene glycol or electric pulse.
87
What are some pre-fertilisation barriers to reproduction across species?
Asynchrony of flowering, floral morphology, self-incompatibility.
88
What are some post-fertilisation barriers to reproduction across species?
Hybrid weakness/ sterility.
89
What is embryo rescue?
Culture embryos that would die, create new hybrids, useful in wide range of species, speeds up breeding.
90
What are examples of uses of plant cells as factories?
Drugs, flavours, dyes, fragrances.
91
How would we use plant cells as factories?
Understand biochemistry, find genes, express in plant cells, harvest chemicals.
92
What are the de-differentiation problems to overcome for plant cells as factories?
Changes in genes expressed, in enzymes produced and in metabolites produced.
93
How many plant species have been screened for their medicinal use?
35,000 - 70,000.
94
How are many compounds now synthesised?
Chemically.
95
What are 11% of the 252 drugs considered as basic and essential by the WHO like?
Still exclusively of flowering plant origin.
96
What is Taxol and where is it from?
Potent anti-cancer drug, binds microtubules, stops cell division, from pacific yew tree.
97
What is the hurdle with companies using plants to produce human pharmaceuticals?
Need to make transgenic plants.
98
What is conventional traditional breeding?
Cross plants of same species and select phenotypes in progeny.
99
What is genetic modification (producing GM plants)?
Construct transgene and transform into plant cells, transgene come from any source, regenerate with desired phenotype.
100
What are the steps of plant transformation?
Assemble transgene in a bacterial plasmid, transfer to plant genome, select plant with new traits,
101
How is Agrobacterium tumefaciens used for genetic modification?
Plant pathogen (crown gall), bacterium delivers own plasmid DNA into plant genome, one gene codes for enzyme to make hormone cytokinin.
102
What is a crown gall?
Mass of undifferentiated cells.
103
How does the Agrobacterium tumefaciens lead to transgenes being inserted into plant chromosomes?
Replace genes which cause crown gall with transgenes.
104
What are the steps of leaf disc transformation?
Put transgene into Agrobacterium, incubate Agrobacterium with lead discs, move leaf discs onto selective medium, wait for shoots and roots to develop, grow plants to maturity.
105
What are the steps of regeneration of plants from tissue culture?
Incubate leaf discs with Agrobacterium, balance cytokinin and auxin to induce callus growth, add more cytokinin to induce shoot growth, add more auxin to induce root growth, transfer to soil, gradually reduce humidity.
106
How can GM plants help?
Increased crop plant yields through protection from pests and pathogens, improvement of nutritional qualities - more vitamins better proteins improved oils more antioxidants, new products - vaccines plastics.
107
How much do pests and pathogens reduce crop yeild?
By 30%.
108
How much does insect damage reduce crop yeild?
By 13%.
109
How can you protect from pests and pathogens?
Bt toxic proteins identified, genes isolated, cloned into plasmids, transformed into plants.
110
What can vitamin A deficiency cause and why is rice low in this?
Causes blindness, rice poor in beta carotene needed for synthesis of Vit A (then low rhodopsin).
111
How many children go blind every year?
250 000 - 500 000.
112
How has rice been engineered to produce beta carotene?
Cloned genes from 2 species: phytoene synthase from narcissus pseudonarcissus, phytoene desaturate from bacterium Erwinia uredovora, produces beta carotene in endosperm.
113
How many amino acids can humans synthesise?
10 out of the 20 amino acids - getting balance of essential amino acids therefore difficult.
114
What are cereals and pulses limited for respectively?
Lysine and methionine.
115
What is engineered into cereals?
Identified proteins rich in Lys.
116
What oils are essential for human health?
Omega-3-long-chain polyunsaturated fatty acids.
117
What are anthocyanins?
Metabolites that give fruit and flowers red to purple colour, polyphenols that act as antioxidants and protect against cancer.
118
What is the black tomato?
Engineered tomato to produce more anthocyanins.
119
How are more antioxidants produced in tomatoes?
Transcription factor gene — transcription factor protein — switches on promoter (anthocyanins biosynthesis genes) — anthocyanins biosynthesis enzymes.
120
What are vaccines?
Immunogenic proteins that stimulate the body to make correct antibody to fight the infection.
121
What are the best plants for plant derived edible vaccines?
Tomatoes, bananas, potatoes.
122
What are advantages of edible vaccines?
No purification needed, easy to harvest, can be stored dried, no contamination with pathogens, no syringes.
123
What are problems with edible vaccines?
Efficiency of expression, regulatory issues, clinical trials.
124
How can transgenes be spread through pollen?
Oil seed rape, transgenic pollen, wind insect pollinators, fertilisation, tras genetic hybrid seed.
125
How can transgenes be spread through seed?
Oil seed rape field at harvest, wind and animal dispersal, natural habitat outside field, wild populations of transgenic oil seed rape, human dispersal.
126
What are effects of spread of transgenes?
Weediness (selective advantage), crop mixing, effects on wildlife (insects affected if toxic).
127
What are examples of public acceptance of biotechnology?
Vegetarian cheese made using GM micro-organisms, cloned human insulin.
128
What is CRISPR/Cas9 gene editing?
Transform guide RNA targeted to gene linked to sgRNA with Cas9 gene, guide RNA has genes that target plant gene of interest, Cas9 makes insertion/deletion in target, mutation to knock out functions.
129
Why can gene editing by considered non-transgenic (different to GM)?
First gen plants have Cas9 transgene, can be segregated out in T1, final plants mutant with no Cas9.
