Download Biotechnology - Genetic Engineering

Biotechnology
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Genetic Engineering
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Genetic Engineering/biotechnology is used to:
1. Produce modify plants and animals.
a. Insert desirable genes from one organism
into another organism.
Examples: Make plants salt resistant
Larger ears and
yields of corn.
Featherless chickens
Make plants insect resistant
Make glow in the dark mice and bacteria
2. Produce medicines like insulin and human growth hormone.
a. Insert the human gene for making these proteins into a bacteria
cell and have the bacteria “mass produce” these much needed
proteins for us.
3. Solve crimes
-Create a “DNA fingerprint”
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4. Determine parentage. Who’s your daddy?
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All forms of genetic engineering revolve around the production of recombinant
DNA and the use of restriction enzymes.
Recombinant DNA:
Restriction Enzymes: These are enzymes naturally occurring in bacteria. The
bacteria use these enzymes to protect themselves from viruses invading them.
Restriction enzymes “cut” the DNA the virus injects into them so that the virus
cannot be reproduced. Act like “molecular scissors”.
Scientist use restriction enzymes to “cut” out genes from sequences of DNA.
There are 75 different known kinds of restriction enzymes, all named after the
bacteria where they were obtained from.
Each restriction enzymes recognize and cuts DNA at a specific sequence of 4 to 6
base pairs.
Example: EcoRI……..restriction enzyme derived from Ecoli bacteria
Recognition site: GAATTC- Cuts DNA between the G and the A
Creates “Sticky ends”
Other examples of restriction enzymes include:
Using restriction enzymes to create “recombinant DNA”:
A. Making Humalin (human insulin made by bacteria)
1. Locate desirable gene. Gene for human insulin is located on
chromosome #12.
2. Add restriction enzyme EcoRI to cut out this desirable gene.
3. Add same restriction enzyme to plasmid of bacteria.
4. Create complementary sticky ends.
5. Allow bacteria to use its _________to pick up desirable gene from its
environment.
6. Add _________to bond complementary sticky ends together creating
recombinant DNA.
7. Allow bacteria to reproduce ________creating many copies of the
recombinant DNA.
8. Allow bacteria to go through protein synthesis creating the human
insulin protein for us very quickly and in large quantities.
B. Creating a DNA fingerprint:
1. Collect DNA from any cell on a person’s body.
2. Add restriction enzyme to the DNA.
3. Restriction enzyme “cuts” the DNA into many pieces every time it
recognizes its specific recognition site.
4. Place DNA sample into the gel electrophoresis apparatus.
5. One end of apparatus is negative and the other is positive (like a
battery). DNA is negative.
6. Turn on electricity.
7. DNA which is negative is picked up by current and carried towards the
positive end of the apparatus because opposites attract.
8. The different size DNA fragments travel different distances. The largest
fragments move the least distance and the shorter fragments move the
most.
9. A dye is added and a banding pattern is revealed. This banding pattern
is unique to everyone and is called a DNA fingerprint.
DNA fingerprint used to solve a crime:
DNA fingerprint to prove parentage: