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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.