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• Is it morally right to treat animals like factories?
• Cows treated with BST have an increased incidence of
udder infections (greater discomfort).
•Will higher production cause prices to drop?
• Does the technology unfairly favor large farms?
• Are longer-term studies needed to rule out health effects?
• How can weknow that it is safe?
• insecticidal activity
• resistance to herbicides
•altered flower pigmentation
• tolerance of environmental stresses
• improved nutritional quality of seed proteins
• improved taste and appearance
how plants get new genes
Replace genes in tumor like substance and infect plants
genetically modified to produce medicine
malaria and chlorea
• Mastitis (bacterial disease in cows) costs the US
dairy industry billions of dollars annually
• Transgenic cows have beengenetically engineered
to secrete lysostaphin in their milk, which kill
•Bt crops could damage migratory insects
•HT genes could spread to native plants
(1) How do we dispose of large quantities of wastes that are
(2) How do we remove the toxic substances
that have accumulated at dump sites, in
the soil, and in water systems over the last
•Exposure to chemicals can lead to cancer or other health problems
•Cancer clusters in communities near contaminated areas
•Heavy metal poisoning in human populations (e.g. lead poisoning
from contaminated soil or housing)
•Tumors on animals living on lands contaminated with nuclear
•Chernobyl: massive birth defects in affected populations
• Chemicals used in processing - e.g. semiconductor fabrication
• Low-value byproducts - e.g. petroleum refining
• Medical waste
• Solvents from dry cleaning
• Solvents, paints, motor oil
• Oil spills
• Leaking storage tanks
Dr. Ananda Chakrabarty
(1) Bacteria and other microorganisms can thrive in the most extreme
and inhospitable environments:
• deep ocean
• hot sulfur springs
• pools of sulfuric acid in mines
(2) They can use almost anything as a fuel source:
(3) Using genetic engineering, it is easy to add capabilities to bacteria
(1) insert several plasmids into a bacterium.
(2) insert one plasmid containing genes for several enzymes
(3) use a colony of several bacteria (aconsortium)
– the use of plants for
biological remediation of environmental
Plants use roots to eliminate toxins
The degradation or breakdown of
organic contaminants by internal
and external metabolic processes
driven by the plant.
Toxic --> Non-toxic
The process where plant roots uptake metal
contaminants from the soil and translocate them
to their above soil tissues.
Disposed of and can be mined for the minerals
Phytovolatilization is the process where
plants uptake contaminaints which are
water soluble and release them into the
atmosphere as they transpire the water.
The contaminant may become modified
along the way, as the water travels along
the plant's vascular system from the
roots to the leaves
• Biomining takes advantage of
extremophiles (archaebacteria) that
can live in extremely acidic and harsh
• Billions of bacteria are employed in
the mining industry, extracting iron,
gold, silver, cobalt, and other minerals
Usually exploits bacteria that naturally are found near
the mine/tailings. Some are genetically modified and
used in processing tanks.
Enzymatic DNA synthesis of DNA can
be repeated many times using the
polymerase chain reaction.
Start with a mixture of:
primers (probes for the template ends)
free nucleotides (A, T, G, and C)
(1) Heat to 95°C, dsDNA
comes apart to form
(2) Complementary DNA
primers attach to
templates when you cool
to about 60°C.
(3) DNA polymerase will
make copies of DNA
starting at the location of
an attached primer.
(4) Repeat steps 1-3.
The number of copies approximately doubles after each cycle.
Only DNA that is complementary to the added primers is duplicated.
• Used to characterize biological samples for legal proceedings; to
“match” sample DNA with DNA taken from a defendant or to rule
out the possibility of a match.
• Also used for paternity testing since the DNA fingerprint of a
child is a composite of the patterns of the mother and father
In principle, the entire chromosomal DNA (genome) could be
sequenced and compared, but that would be outrageously expensive.
Also only recently possible.
Often, just a small quantity of DNA has been found at the place of
the crime. Using the PCR-technique DNA can be amplified in a
test-tube into a large quantity, so that a genetic fingerprint can be
taken. These fingerprints are compared then with the DNA-profile
of the suspect.
(1)Digest sample DNA with a restriction endonuclease. This results in
a distribution of fragments with various sizes.
(2)These fragments are separated by size by placing them on a gel
exposed to an electric field that forces them to move. Smaller
fragments move through the gel more easily and travel farther.
(3)Labeled probes are added that bind to certain sequences within the
(4) Images of the radioactive labels show distinctive “bands” that
indicate the sizes of the fragments that represent the distinctive
distances between restriction enzyme binding sites.
In 1990, the US started a project to map and sequence
the entire human genome. It was expected to take 15
years but was finished in 2000 (‘first draft’), sooner than
This means that the locations and DNA sequences of all
genes are now determined, although the functions of all
the genes are certainly not known.
The next step is to understand the functions of all the
genes and to study thevariations in the gene sequences
(polymorphism) from person to person.
identify all the approximate 20,000- 25,000 genes in
determine the sequences of the 3 billion chemical
base pairs that make up human DNA,
store this information in databases,
improve tools for data analysis,
transfer related technologies to the private sector, and
address the ethical, legal, and social issues (ELSI)
that may arise from the project
• Only about 2 percent of bp make up coding
sequences—24,000 genes. Each gene must
code for several proteins.
• An average gene has 3,000 base pairs.
•98% of all our DNA doesn’t do anything!!
• All human genes have many introns
(regions of the DNA that don’t code for
• Over 50 percent of the genome is repetitive
• 99.9 percent of the genome is the same in
• Genes are not evenly distributed over the
• There are many genes with unknown
• Should insurance companies charge higher
premiums for people who are predisposed to
various genetic diseases?
• Example: BRCA1 gene (breast and ovarian
cancer), which is easily identified. Insurance
companies know they will potentially spend lots
of money treating these patients…
• Do potential employers have a right to obtain
information regarding genetic predisposition of
of modified nucleotides (ddNTPs).
dNTPs contain the sugar 2‐deoxyribose
ddNTPs contain the sugar 2,3‐dideoxyribose.
Like dNTPs, ddNTPs are picked up by DNA
polymerase and added to a growing DNA chain.
ddNTPs lack a hydroxyl group at the 3 position,
however, so no new nucleotide can be added after a
ddNTP, and synthesis ends.
•Sequencing uses PCR (polymerase chain reaction)
•Sequencing begins by denaturing a fragment of DNA.
•The single‐stranded DNA is mixed with DNA polymerase,
short primer strands, the four normal dNTP substrates, and
small amounts of the four ddNTPs, each with a fluorescent
•In solution, DNA polymerase synthesizes strands of DNA
using mostly the normal dNTP substrates.
•When DNA polymerase encounters a ddNTP, chain growth
•The result is a solution with template DNA strands and
shorter complementary strands, each one ending with a
fluorescently tagged ddNTP.
•The new strands are denatured from the templates and
separated byelectrophoresis, a technique that separates
strands by length.
•The shortest fragments should be one base longer than the
•The color of the fluorescent tag at the end of this sequence
indicates the type of ddNTP that was added.
•If this was ddATP, for example, then the first base on the
template strand (after the primer sequence) is T.
•The remainder of the bases on the template strand can be
determined in a similar manner.
A strategy based on theprinciples of biological design.
Not necessarily using biological materials or methods directly
During the day: As day heats up, termites plug holes near base
During the night: Air cools, termites dig new vents, warm air escapes through
chimney and draws in cooler air.
• Two-billion spatulashaped
• Filaments interact on
a molecular level with
surface (through van
der Walls forces)
•molecular machines (small)
• self-assembly = spontaneous, parallel fabrication (cheap)
• combinatorial, trial and error design strategy (evolution)
• factories (cells) that respond to signals (smart)
• factories that make copies of themselves (self-replicating)
composites: mixtures of two or more components
example: bone - hard and tough
laminates: layered sheets
example: bark - tough and flexible
protective coatings: a thin surface layer of material
examples: viral casings, cell walls & membranes
fibers(tensile strength and flexibility)
particles(strong and hard, but flexible
A nanocomposite of alumina and
carbon nanotubes has three times
the toughness of pure alumina.
A hydrogen atom within one water molecule is attracted
to an oxygen atom in a neighboring molecule
Bumpy wax coating causes super hydrophobic
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