Exam 3 Flashcards
1
Q
What are microbes?
A
Tiny organisms, such as bacteria, fungi, algae, and protozoa, that are too small to be seen individually by the naked eye.
2
Q
What percentage of bacterial species have been identified and studied?
A
Less than 1%, though they are estimated to comprise over 50% of the earth’s biomass.
3
Q
What is bioprospecting?
A
The discovery and development of new products from biological resources.
4
Q
Name applications of microbial enzymes in food production and research.
A
- Taq DNA polymerase used in PCR because they are isolated from heat loving bacterium
- Cellulase, makes animal food more digestible and is used to create worn out look on jeans
- Subtilisin, used in laundry detergents (breaks down stains, etc.)
5
Q
What is the purpose of the Yeast Two-Hybrid System?
A
To determine if two proteins, ‘A’ (Bait) and ‘B’ (Fish), interact with each other.
6
Q
How does the Yeast Two-Hybrid System indicate protein interaction?
A
If proteins ‘A’ and ‘B’ interact, they bring together a DNA binding domain (A) and an activator domain (B), resulting in the expression of a reporter gene, such as lacZ.
7
Q
What is CRISPR (clustered regularly interspaced short palindromic repeats)?
A
A prokaryotic immune system that helps bacteria remember and defend against viruses by using repeated DNA sequences called CRISPR in their genomes.
8
Q
How does CRISPR provide immunity?
A
By using segments of spacer DNA, sequences from previous exposures to foreign DNA, such as viruses or plasmids.
9
Q
What is Cas9 and its function in CRISPR?
A
Cas9 is protein that works together with guide RNA to cut DNA at specific target sequences.
10
Q
Cas genes vs Cas9
A
Cas genes are what encoed the proteins that work with the CRISPR sequences.
Cas9 is a protein encoded by the genes, which does the cutting.
11
Q
What does Cas9 require to cleave target DNA?
A
Cas9 is complexed with a crRNA (crispr RNA) and a separate trans-activating crRNA (tracRNA) to cleave target DNA. The crRNA guides Cas9 to the target DNA sequence, while the tracRNA helps stabilize the Cas9-crRNA complex and facilitates cleavage
12
Q
Describe the basic steps of gene editing using CRISPR/Cas9.
A
Scientists design a guide RNA that matches the target DNA sequence.
Cas9 uses this guide RNA to find the target DNA.
Once located, Cas9 makes a cut in the DNA.
Then a new piece of DNA can be inserted, and enzymes help repair the break in the DNA.
13
Q
CRISPR was named the biotech breakthrough by who
A
By the American Association for the Advancement of Science (AAAS) in 2015
14
Q
How are microbes used in food production?
A
They are used in both traditional and modern biotechnology to produce bread, yogurt, cheese, and alcoholic beverages.
15
Q
What was the first recombinant DNA food ingredient approved by the FDA?
A
Chymosin; used to make cheeses (1999).
16
Q
What is rennin, and how is it used in cheese production?
A
An enzyme traditionally extracted from the stomachs of calves and used to create curds in cheese production.
17
Q
What is chymosin, and why is it used instead of rennin?
A
A cloned form of rennin produced in bacteria. It is less expensive and easier to produce.
18
Q
What is fermentation?
A
The process of deriving other compounds from sugars in the absence of oxygen.
19
Q
What is lactic acid fermentation used for?
A
To make yogurt, sour cream, sauerkraut, vinegar, and certain cheeses and breads.
20
Q
What is alcohol fermentation used for?
A
To make beer, wine, and champagne.
21
Q
How are bacteria used to produce therapeutic proteins?
A
Bacteria are used to produce medically important proteins, such as insulin, which can be used in human treatments.
22
Q
What was the first recombinant protein expressed in bacteria for human use?
A
Insulin was the first recombinant molecule expressed in bacteria for human use, developed in 1978.
23
Q
What is Humulin, and when was it commercially available?
A
Brand of synthetic insulin, made by Genentech in 1982.
24
Q
Who developed the first vaccine?
A
Edward Jenner in 1796.
25
What virus did Jenner use to vaccinate against smallpox?
Cowpox.
26
What are vaccines, and how do they work?
Vaccines contain parts of a pathogen or whole organisms that stimulate the immune system against infection by that pathogen.
27
What is an antigen?
A foreign substance, such as bacteria, fungi, viruses, proteins, lipids, or carbohydrates, that stimulates an immune response.
28
How does the immune system respond to antigens?
Antibodies are produced in a process called antibody-mediated immunity, involving B cells and T helper cells.
29
What do B and T helper cells do?
- B cells recognize and bind to the foreign antigen.
- With the help of T helper cells, B cells undergo activation to form plasma cells to produce antibodies.
30
What role do antibodies play in immunity?
They bind specifically to antigens, marking them for destruction by macrophages, which phagocytize the antibody-coated antigens.
31
What are the 4 major strategies in making vaccines?
- Subunit Vaccines
- Attenuated Vaccines
- Inactivated (killed) Vaccines
- mRNA Vaccines
32
What are subunit vaccines?
Subunit vaccines are made by injecting portions of a pathogen's structure, like purified proteins, to stimulate an immune response.
33
What are attenuated vaccines?
Attenuated vaccines use live pathogen that are weakened so they can't replicate, creating immunity without causing disease.
34
What are inactivated (killed) vaccines?
Inactivated vaccines are made from pathogens that have been killed or inactivated, making them safe for vaccination.
35
What are mRNA vaccines?
mRNA vaccines contain non-replicating mRNA in a lipid nanoparticle, which enters cells and teaches the immune system to recognize the pathogen (e.g., Pfizer/BioNTech and Moderna COVID-19 vaccines).
36
How are many subunit vaccines produced?
They are made using recombinant DNA technology, where vaccine proteins are produced in microbes (e.g., Hepatitis B and HPV vaccines).
37
How is the Hepatitis B vaccine created using recombinant DNA?
Genes for viral surface proteins are cloned into plasmids and introduced into yeast. The yeast produces fusion proteins that are purified for the vaccine.
38
What is Gardasil?
Gardasil is a vaccine that protects against nine strains of human papillomavirus (HPV).
39
What are some major diseases targeted for vaccine development?
Biotechnology companies are working on vaccines for diseases like influenza, tuberculosis, malaria, HIV, and COVID-19.
40
Why is sequencing microbial genomes important?
Helps identify genes involved in metabolism, cell division, and disease, and finds new strains for tasks like bioremediation and identifying pathogens.
41
What was the impact of sequencing the Streptococcus pneumoniae genome?
Led to the discovery of new surface protein genes, resulting in improved vaccines and treatments, especially for children.
42
What is metagenomics?
The study of genetic material recovered directly from environmental samples, providing insight into microbial communities in various ecosystems.
43
What is the microbiome?
The collection of genomes of microorganisms in a specific environment, such as the human body.
44
What is the Human Microbiome Project?
Launched in 2008, this NIH project aimed to sequence genomes of human-associated microbes to better understand health impacts and cataloged over 2,200 genomes by 2019.
45
What are the goals of the Human Microbiome Project?
The project aims to determine if people share a core microbiome, understand microbial community formation, study health-related changes, and develop microbiome analysis methods while addressing ethical issues.
46
What is microbial diagnostics?
Involves techniques like RFLP analysis, PCR, and DNA sequencing to detect and track microbes, particularly in clinical and food samples.
47
How are microarrays used in tracking contagious diseases?
Microarrays test up to 50,000 species in parallel to detect pathogens, examine host responses, and identify gene expression "signatures" for specific pathogens
48
Why is plant transgenics important for agriculture’s future?
With a doubling world population and limited arable land growth (increase by only 10%), transgenics helps improve crop productivity by directly transferring beneficial genes, meeting food demands more efficiently.
49
What is plant transgenesis?
The direct transfer of genes to plants to develop traits like vaccine production, pesticide production, and herbicide resistance.
50
What are some standard methods for plant transgenesis?
Selective breeding/hybridization
and cloning.
51
What is conventional selective breeding and hybridization?
It involves sexual crossing between two lines and backcrossing hybrids with parents.
This method can take years and may include polyploid plants to enhance traits.
52
What are polyploid plants?
Plants that have multiple sets of chromosomes, (can increase desirable traits especially size). Colchicine is used to make polyploid plants by causing cells to have extra sets of chromosomes.
53
What is plant cloning?
Process of growing new plants from a single cell, allowing for the consistent reproduction of desirable traits.
54
what are plant cloning techniques
1. protoplast fusion w plant tissue culture (PTC)
2. leaf fragment technique & Ti plasmid (w PTC)
3. gene guns w PTC
4. chloroplast engineering w PTC
5. antisense technology
55
What is a protoplast?
A plant cell with its cell wall removed, usually with the enzyme cellulase, to allow fusion with another cell.
56
What is protoplast fusion?
Protoplast fusion combines two plant cells without cell walls (protoplasts) using polyethylene glycol, allowing for hybrid plant development. Example: broccoflower.
57
What effect does an equal ratio of cytokinin and auxin have on plant cells?
The formation of an undifferentiated callus.
58
What effect does a higher level of cytokinin and lower level of auxin have on plant cells?
It promotes the growth of shoot buds.
59
What effect does a higher level of auxin and lower level of cytokinin have on plant cells?
It stimulates root formation.
60
Plant cloning: leaf fragment technique
Small discs are cut from a leaf and cultured with genetically modified Rhizobium radiobacter (formerly Agrobacterium tumefaciens) to introduce new genes.
61
How does Rhizobium radiobacter assist in plant gene transfer?
It contains a Ti plasmid with T-DNA that integrates into the plant cell's DNA, allowing genetic modification.
62
What is the purpose of a gene gun in plant cloning?
Gene guns are used to blast DNA-coated metal beads (e.g., tungsten or gold) into plant or animal cells to introduce new genes.
63
Where are gene guns usually aimed at
Nucleus or chloroplast.
64
Why are gene guns useful in certain plants?
They are effective in plants that are resistant to Rhizobium radiobacter, like monocots, allowing for genetic transformation.
65
What is a marker gene and how is it used in gene gun technology?
Marker genes, like antibiotic resistance, are used to identify cells that have been successfully genetically transformed.
66
What are the benefits of chloroplast engineering in plants?
Chloroplast DNA can accept multiple new genes, is separate from genomic DNA, and has a low risk of gene transfer to other plants via pollen.
67
Types of mRNA in Plant Transgenesis
- polycistronic mRNA
- monocistronic mRNA
68
What is polycistronic mRNA and where is it found?
Found in prokaryotes, can code multiple proteins, transcribed from more than one gene and has many start and stop codons.
69
What is monocistronic mRNA and where is it found?
Found in eukaryotes, codes a single protein, transcribed from one gene and has one start and stop codons.
70
What is antisense technology?
Involves inserting a complementary copy of a gene
the gene encodes an mRNA molecule (antisense molecule) which binds to and inactivates normal mRNA (sense).
71
What is an example of antisense technology?
The Flavr Savr tomato, which uses antisense technology to slow down fruit softening.
72
What are some practical applications of plant biotechnology?
Vaccines for plants, genetic pesticides, herbicide resistance, enhanced nutrition, and the future of pharmaceuticals to fuel.
73
How are vaccines for plants created?
A gene from a virus, such as the Tobacco Mosaic Virus (TMV), is inserted into a plant's DNA. The protein produced stimulates the plant's immune system, making it resistant to the virus.
74
What is Bacillus thuringiensis (Bt)
A bacterium that produces a protein that kills harmful insects and their larvae
75
how is Bacillus thuringiensis (Bt) used in plant biotechnology?
Bt Cry genes can be inserted into plants to create a built-in defense against harmful insects, though there is controversy about its impact on monarch butterflies.
76
What does Bt Cry do to insects?
Crystalized proteins fuse to the gut lining.
77
What is an example of herbicide resistance?
Resistance to glyphosate
78
What does glyphosate block in plants?
Glyphosate blocks the enzyme EPSPS, which is involved in a key biochemical pathway.
79
How do transgenic crops resist glyphosate?
Transgenic crops produce an alternative enzyme to EPSPS, which is not affected by glyphosate, allowing the plants to survive even when glyphosate is applied.
80
What is the downside of herbicide-resistant crops?
Glyphosate-resistant weeds have evolved, meaning that the herbicide is no longer as effective at controlling these weeds
81
What is the purpose of engineering Golden Rice?
Golden rice has been engineered to contain large amounts of beta carotene, which the body converts into vitamin A, addressing vitamin A deficiency in populations.
82
Why have farmers not planted Golden Rice as of 2011?
Environmental organizations have raised concerns, which have led to resistance against planting Golden Rice, despite its potential nutritional benefits.
83
Future of Plant Biotechnology in Pharmacology
- Plants can serve as ideal protein factories for producing medicines.
- Molecular farming can be used to grow edible vaccines (do not require refrigeration).
- Plants can produce phytochemicals, antibodies, blood products, cytokines, growth factors, hormones, and recombinant enzymes.
84
Where are biofuels derived from?
Biological products like plants
85
How many gallons of gasoline is needed to produce 10 of kernel corn ethanol?
7 gallons
86
Scientists aim to convert plant waste, like husks and stems into...
Sugars that can be used to produce ethanol, offering an alternative to fossil fuels.
87
What might be the next alternative to petroleum?
Duckweed.
88
Human Health Concerns in Genetic Engineering
- Allergic reactions
- Spread of antibiotic-resistance marker genes to disease-causing bacteria in humans
- Possible cancer risk
"Science has not supported these concerns as of now."
89
Environmental Concerns in Genetic Engineering
- There are concerns that genes for pest or herbicide resistance could spread to weeds.
- Most experts believe this won't happen, though further studies are needed.
90
Name associations in charge of regulations
- FDA food regulation on the market
- USDA oversees growing practices
- EPA controls use of Bt proteins/other pesticides.
91
Uses of Genetically Engineered Animals
- Medical treatments development
- Improvement of the food supply
- Enhancement of understanding of animals and humans
92
Animal Models in Biotechnology...
Animals share genetic and physiological similarities with humans, which is essential for research.
93
Key breakthroughs enabled by animal research:
- Polio vaccine
- Dialysis
- Cataract surgery
94
Animal health breakthroughs due to biotech include:
USDA-approved 111+ veterinary biologics and vaccines for conditions like heartworm, arthritis, and parasites.
95
Common Animal Models Used in Research
Purebred mice and rats are most commonly used.
96
Other species used in research and their match percentage to humans
Zebrafish (70%)
Fruit flies (44%)
Nematodes (35%)
97
What animals make up less that 1% of total research animals
Dogs, Cats, Monkeys, and Chimps.
98
Zebrafish as an Ideal Model Organism
- 3 cm long, allowing large numbers to be housed in small spaces.
- Short generation time
- 200 progeny per female per week.
Embryogenesis completed in 120 hour
- gut, liver, and kidneys develop within 48-72 hours.
- Can be used to test drugs for toxicity or adverse effects in 5 days.
99
What zebrafish is a model to study migration of cancer cells
Casper.
100
Rats in Drug Testing
- Used for early drug toxicity tests due to human-like drug responses.
- Larger size aids surgical/physiological testing.
- Extensive toxicology data available for rats.
101
Use of Cats, Dogs, and Primates in Research
Cats, dogs, and primates are used selectively for relevant biological similarities to humans.
Examples:
- Dog cardiovascular/lung systems resemble humans.
- Primates share humans' vulnerability to HIV.
102
FDA Regulations for Drug Testing
- New drugs, procedures, and cosmetics must pass animal safety tests.
- If cell cultures show high toxicity, live animal testing is avoided.
- Two animal species used in pre-clinical testing to detect toxicity.
- Drugs with significant issues don’t proceed to clinical trials.
103
What can animal models help determine
- rate of absorption
- specific chemical metabolism
- time required to excrete the substance
104
Alternatives to Animal Models
Cell Culture:
- Less expensive than animal research.
- Used to screen for toxicity and study cell biology.
- Can’t provide data on whole-body effects.
105
Alternatives to Animal Models
Computer Models:
- Cost-effective simulations of molecular/chemical interactions.
- Limited by existing biological knowledge and programming.
Example: Detected reproductive issues with finasteride.
106
Federal Animal Welfare Act
Law from 1966 setting standards for:
Animal housing, feeding, cleanliness, and medical care in research.
107
What is the Institutional Animal Care & Use Committee (IACUC)?
A federally mandated committee present at each research institution to oversee animal research protocols, ensure the need for animal use is justified, select appropriate species, and devise plans to use as few animals as possible.
108
What is the Institutional Review Board (IRB) responsible for?
Overseeing U.S. federally funded research involving humans.
109
What are the three levels of IRB review?
Exempt, expedited, and full board.
110
What is required for researchers to receive NIH, FDA, or CDC funding in animal research?
Researchers must follow standards of care outlined in "The Guide for the Care and Use of Laboratory Animals," formulated by the National Academy of Sciences.
111
What are the "3 R's" in animal research?
- Reduce the number of higher species,
- replace animals with alternative models,
- refine tests to improve animal welfare.
112
How is veterinary medicine involved in clinical trials?
Veterinarians participate in research, and findings in one species can be applied to others. For example, the BRCA1 gene is similar in humans and dogs.
113
Give an example of a veterinary treatment that applies to multiple species.
Hyperthermia of a tumor site combined with IL-12 injection is more effective in cats than IL-12 therapy alone.
114
What is embryo twinning in cloning?
Splitting embryos in half to produce identical twins, a common practice in the cattle industry.
115
What was the first animal cloned from an adult nucleus, and why was this significant?
Dolly the sheep, cloned in 1996, was the first animal cloned from an adult cell, representing a breakthrough in cloning technology.
116
Describe the basic steps in creating a clone from an adult animal.
1. Enucleation of an egg cell, 2. Transfer of a donor cell nucleus, 3. Embryo transfer to a surrogate for gestation.
117
Why are clones not exactly identical to their donors?
Clones are shaped by different experiences and environments, which affect their development.
118
What is the success rate of cloning, based on Dolly the sheep and Carbon Copy (Cc) the cat?
The success rate is low; Dolly was the result of 277 attempts, and Cc was the only success out of 87 implanted embryos.
119
What is a potential issue with the aging process in clones?
Clones may appear to age prematurely due to shortened telomeres, although new research suggests this may not always be the case.
120
Why is cloning considered a young science?
Cloning is still in its early stages and requires much experimentation.
121
Why is cloning not a practical solution for human organ transplants?
Cloning raises profound ethical questions, and it would take years for a human clone to mature enough to donate organs.
122
How can clones of laboratory animals benefit medical research?
Clones with identical genetics make it easier to analyze treatment results, offering insights into cellular and molecular aspects of development, aging, and diseases.
123
What role could clones with unique genotypes play in conservation?
They could help sustain the breeding populations of endangered species.
124
What is pronuclear microinjection in transgenic animals?
A method of introducing transgene DNA directly into the nucleus of an egg or sperm at the earliest zygote development stage, without using a vector.
125
How does retrovirus-mediated transgenics work?
Mouse embryos at the 8-cell stage are infected with defective retroviruses carrying the desired transgene before implantation.
126
What is a limitation of retrovirus-mediated transgenics?
The size of the transgene that can be introduced is limited.
127
What is the embryonic stem cell method for introducing new genetic material into animals?
DNA is injected into embryonic stem cells, which absorb the DNA and are then added to a blastocyst.
128
How does sperm-mediated transfer introduce genetic material?
It uses "linker proteins" to attach DNA to sperm cells, which then deliver the DNA during fertilization.
129
How are gene guns used in introducing new genetic material?
Gene guns can deliver DNA directly into animal cells by shooting microscopic DNA-coated particles into them.
130
What is CRISPR in the context of genetic modification in animals?
CRISPR is a gene-editing tool that allows precise modifications to DNA within animal cells.
131
How can gene transfer improve livestock productivity?
Gene transfer can lead to faster growth rates and leaner growth patterns, improving the efficiency of livestock.
132
What is the result of using an AFP promoter in transgenic livestock?
The AFP promoter can accelerate growth rates, making the animals quicker to market and less costly to raise.
133
How can gene transfer produce healthier foods?
By tweaking genes responsible for cholesterol production, healthier, lower-cholesterol eggs can be produced.
134
What is significant about Herman, the transgenic bull?
Herman carries the human gene for lactoferrin, which increases the availability of iron in milk.
135
Example of animals engineered to resist diseases?
Transgenic dairy cows resistant to mastitis.
136
What is mastitis and how does it affect dairy cows?
Mastitis is a contagious condition caused by Staphylococcus aureus, costing billions annually in the dairy industry.
137
How do transgenic dairy cows resist mastitis?
The cows have a gene that produces lysostaphin, which kills Staphylococcus aureus.
138
What is the EnviroPig developed by the University of Guelph?
The EnviroPig is a transgenic pig that expresses the enzyme phytase in its saliva.
139
What does the enzyme phytase do in the EnviroPig?
Phytase degrades indigestible phytic acid, releasing phosphate that the pig can digest.
140
What environmental benefit does the EnviroPig provide?
The EnviroPig produces substantially less phosphorus in its urine and feces, reducing the environmental impact of pig farms.
141
How can transferring antimicrobial genes to farm animals improve food safety?
It could reduce the number of food poisoning deaths in the U.S. each year by making animals more resistant to harmful pathogens
and reduce the use of antibiotics.
142
What process is used to create transgenic animals that produce proteins?
Modified embryonic stem cells are placed into a normal embryo and then inserted into a surrogate. After selective breeding, the fully transgenic animals produce milk or eggs rich in the desired protein.
143
Why are goats preferred over cattle for producing transgenic protein in milk?
Goats are used because they reproduce more quickly and are cheaper to raise than cattle.
144
What is Atryn, and why is it important for patients with hereditary clotting issues?
Atryn is an anticlotting protein needed by patients with hereditary clotting disorders to help prevent abnormal blood clotting.
145
How were transgenic goats used to produce Atryn?
Transgenic goats were developed by GTC with Atryn under the control of a mammary-specific promoter, allowing them to produce the protein faster, more reliably, and more cheaply than traditional methods.
146
When did the FDA approve Atryn produced by transgenic goats?
2009.
147
What is Biosteel, and what are its uses?
Biosteel is a protein derived from spiderweb protein, one of the strongest fibers on Earth, used to strengthen bulletproof vests and suture silk.
148
How is Biosteel produced in transgenic animals?
Spiderweb protein genes have been transferred to goats, where the protein is expressed in their milk.
149
What are knockout mice, and how are they genetically engineered?
Knockout mice are genetically engineered mice where a specific gene is disrupted. DNA is modified and added to embryonic stem cells, where it recombines with the existing gene on a chromosome through homologous recombination.
150
What happens after the modification of embryonic stem cells in knockout mice?
The modified embryonic stem cells are introduced into a normal embryo, which is then implanted into a mother. The resulting mouse pup is a chimera, with some cells being normal and some being knockouts.
151
How are complete knockout mice produced?
Two generations of selective breeding are required to produce complete knockout mice.
152
What are knock-in animals?
Knock-in animals involve the substitution of a DNA sequence with a wild-type copy or the insertion of new sequence information not originally found in a genetic locus, such as in gene-rescue experiments.
153
Give an example of a knock-in animal.
An example of a knock-in animal is a mouse engineered to produce human immunoglobulin (Ig).
