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DNA Technology
DNA-Review
● DNA strands are in base
pairing.
● Adenine base pairs with .
● Cytosine base pairs with .
Importance of DNA technologies
● Medicine-insulin
● Forensic sciences-solving crimes
● Environmental sciences-identifying pollutants
● National security-genetic profiles of convicted felons
Examples of DNA Technology
● Gel Electrophoresis (separate DNA molecules)
● DNA Fingerprinting (images of sequences of DNA)
● Transgenic Organisms (organisms that have undergone
genetic changes, GMO’s)
● Bacterial Transformations (insertion of a gene into a
bacteria)
Gel-Electrophoresis“used to make DNA Fingerprints”
● Gel electrophoresis is a laboratory technique used to visualise DNA on a gel
where the DNA molecules are separated according to their size
Gel electrophoresis
Gel-ElectrophoresisHow does it work?
● How it works:Electricity runs through a gel mediumDNA is negatively charged and is attracted to the positive end of the gelSmaller fragments move faster and therefore farther through the gel
Stains or dyes are used to view the bands
How does DNA Fingerprinting work?
http://www.youtube.com/watch?v=ZxWXCT9wVoI
DNA Fingerprinting What does the resulting gel tell a scientist?
● Crime Scenes
● Paternity Test
● Organize DNA fragments to
make it easier for scientist
to study.
So how do get DNA into a gel?
Restriction Enzymes
● Special enzymes that can cut segments of DNA at specific locations
DNA “Scissors” into DNA fragments.
CRISPR/Cas9, a gene editing tool
Cloning
● The process of producing similar genetically identical individuals
● Happens in nature: organisms such as bacteria, insects or plants
reproduce asexually.
● Scientist will use cloning to create copies of DNA fragments, cells or
organisms.
Cloning
Dolly the Sheep
http://www.nytimes.com/video/us/100000002496111/dolly-the-sheep.html
Transgenic Organisms
● A transgenic organism contains a gene or genes
which have been artificially inserted instead of the
organism acquiring them through reproduction.
Transgenic Organisms
Transgenic organisms video
https://www.youtube.com/watch?v=ujZHrR1mro8
https://www.youtube.com/watch?v=8z_CqyB1dQo
Why do GMOS get a bad rep?
● Genetically Modified Organism (GMO) – Organism that has had its DNA artificially altered to enhance usefulness.
Example: Golden Rice
● Genetically engineered to
produce beta-carotene, precursor
of vitamin A.
● Vitamin A deficiency most
prevalent in Africa, can cause
blindness.
● Vitamin A deficiencies is
estimated to kill 670,000 children
under the age of 5 each year.
How do you make a GMO????
http://www.youtube.com/watch?v=2G-yUuiqIZ0
Bacterial Transformation
● This is a very basic technique that is used on a daily basis in a molecular
biological laboratory.
● What does it mean to transform something?● “Think change” “Think Genetic Change”
● A process of an organism taking in foreign DNA and through this the
foreign gene become expressed
Plasmid can be used to transform bacterial
cells
● Discovered in the late sixties and quickly realized plasmids could be used
to make lots of copies of a desired gene.
● A small circular piece of DNA (about 2,000 to 10,000 base-pairs)
● Contains important genetic information for the growth of bacteria (GENES)
Bacterial Transformation video
How does this work?
https://www.youtube.com/watch?v=hSbTWaR6Lzk
Bacterial Transformation-Purpose
● Technique: introduce a foreign plasmid into a bacteria and use bacteria
to amplify the plasmid.
● WHY DO THIS?? Make large quantities of copies .
● Scientist use bacterial transformation to produce large amounts of
proteins, like INSULIN
Insulin-very important
● Regulates the metabolism of carbohydrates and fats by promoting the
absorption of glucose from the blood all needed organs of the body.
● A person who has diabetes has either Type 1 or Type 2.
o Type 1: your pancreas does not make insulin
o Type 2: your body does not use insulin properly, insulin resistance
Bacterial Transformation used to make insulin.
1. Insert DNA into Plasmid
2. Insert Plasmid back into
bacteria
3. Plasmid will multiply
4. Bacteria will Reproduce
5. Bacteria Produce Proteins
6. Isolate the product
Genome
● A genome is an organism’s complete set of DNA, including all of its genes.
● In humans, a copy of the entire genome—more than 3 billion DNA base
pairs—is contained in all cells that have a nucleus. 6 Feet long.
Human Genome Project 2003
● Determined the sequence of the human genome and identified the genes
within genome.
● As researchers learn more about the functions of genes and proteins, this
knowledge will have a major impact in the fields
o medicine
o biotechnology
o life sciences.
Human Genome Project Goals
● Accurately sequence 3 billion DNA base pairs within the human genome
● Find all of the estimated 20,000 to 25,000 human genes
o Find genes which define our phenotypes
o Find genes whose alteration leads to disease
Gene Therapy-developed from the Human
Genome Project!
● Insert normal genes into cells
o Replace missing or
defective genes
o Hopefully can correct
genetic disorders.
● Gene therapy is currently only
being tested, on humans, for
the treatment of diseases that
have no other cures.
http://www.youtube.com/watch?v=e
R_vfeoOSQg
Example: Cancer, Leukemia
● Patients white blood cells removed
and treated with a virus
● Genetically altered cells to seek a
protein that sits on the surface of
the cancer cells.
● White blood cells returned to the
patients
● White blood cells attack cancer cells
● 26 experienced complete remission.