Transcript DNA Technology - De Anza College

DNA Technology
Activity: Restriction enzymes
What is DNA Technology?
Its a set of methods
Name some of these methods: 1
Cut DNA into segments
What cuts the DNA?
Restriction enzymes
Another method?
Gel electrophoresis
Why use it?
To separate segments
2
Activity: Cloning a gene in bacteria
What is done with the segments?
Transfer to another organism
(E. coli)
What are they transferred into in E. coli?
A plasmid
3
(also called a ‘vector’ )
What are these ‘new’ plasmids called?
Recombinant DNA plasmids
4
What is done with these ‘new’ plasmids?
Put back into E. coli
5
E. Coli continues living
and dividing
But, what new capability does E. coli have?
Produces a ‘new’ protein
From that gene segment
6
What are the methods used for?
Used to study and manipulate genetic material
Called?
Genetic engineering
Or, recombinant DNA technology
The basic techniques of genetic engineering
have many applications
DNA Technology and useful
products
What was the world’s first genetically
engineered pharmaceutical product?
Insulin
Before modern biotechnology, where
did insulin come from?
Cows, pigs, horses
Why is the genetically engineered
insulin better?
Its made from a human gene
Does not cause allergic reactions
Ample supply available
What is the name of the technique used
to make insulin?
Recombinant DNA technology
gene A discrete unit of hereditary information consisting of a specific nucleotide
sequence in DNA (or RNA, in some viruses)
How does the recombinant DNA technique
work?
A quick look:
The gene is inserted into
the DNA of another
(host) cell
The host cell now contains
recombinant DNA
DNA carrying a gene of
interest is taken from a
(e.g., a human) cell
The host cell multiplies
What happens to the DNA?
The desired protein is
produced
recombinant a molecule carrying DNA from more than one organism
Humulin production
• Huge vats
• Liquid culture
of bacteria
• Bacteria
contain insulin
gene
• And, insulin is
produced
Insulin collected, purified, tested for quality, packaged
Where else is recombinant
DNA used?
To introduce a gene into crop plants
The gene gives resistance to
specific herbicides
What other crop plants can you
think of?
e.g., rice, soybeans, cotton
Look at the golden rice activity
Have you heard about the Flavr Savr
tomato?
Its been genetically engineered…
To reduce rate of spoilage
What does this mean?
… a marketing advantage
It can sit on the shelf longer
It can be picked at a later stage of ripeness
How is the stone washed
denim look achieved?
Via genetic engineering…
• Recombinant DNA techniques are used
• To clone cellulase genes in bacteria
• To produce large quantities of cellulase
To sell to textile manufacturers
What does the enzyme do?
It partially breaks down the cotton fibers
(They also wear out faster!)
Have you ever skied on artificial
snow?
This is another example of
recombinant (r) DNA technology…
What has r DNA technology done
for skiing?
Increase expression of a bacterial protein
Called SnowMax
Used in snow making machines
Mix cold water and protein & huge amounts of snow are produced
Activity: Applications of DNA technology
Gel electrophoresis
What would you do if you needed to analyze the DNA
from a crime scene?
Collect DNA samples
1
From what?
Then what’s next?
2
3
The crime scene itself (1)
And any suspects (2, 3)
• Extract DNA
• Cut &/or amplify the DNA samples
What are these fragments called?
Restriction fragments
Activity: Gel electrophoresis of DNA
• Load DNA into wells
• Turn on power supply
• Watch fragments travel through gel
• Observe separated
fragments
What do you know about DNA to cause the fragments
to travel in the gel?
-
(PO4 )
Length
1
2
1
2
3
3
Compare the results
Which DNA sample matches DNA from the crime
scene?
Do you think this person is guilty of the crime?
What is this field of science called?
Learning check
1. A recombinant DNA molecule _____.
a. is necessary for manufacturing protein on a large scale
b. is produced in yeasts
c. is the product of a defective gene
d. requires DNA from two different individuals-perhaps
even individuals from different species
e. requires the use of cDNA
Learning check
1. A recombinant DNA molecule _____.
a. is necessary for manufacturing protein on a large scale
b. is produced in yeasts
c. is the product of a defective gene
d. requires DNA from two different individuals-perhaps
even individuals from different species
e. requires the use of cDNA
2. This is a DNA fingerprint exhibiting samples from a
victim, two suspects, and the crime scene.
Which of these DNA fragments is common to both
the victim and Suspect 1?
A
B
C
D
E
Activity: DNA Fingerprinting
2. This is a DNA fingerprint exhibiting samples from a
victim, two suspects, and the crime scene.
Which of these DNA fragments is common to both
the victim and Suspect 1?
A
B
C
D
E
3. This is a DNA fingerprint exhibiting samples from a
victim, two suspects, and the crime scene.
Which of these DNA fragments is common to both
the victim and Suspect 2?
A
B
C
D
E
3. This is a DNA fingerprint exhibiting samples from a
victim, two suspects, and the crime scene.
Which of these DNA fragments is common to both
the victim and Suspect 2?
A
B
C
D
E
4. Why is Suspect 1 considered more likely to have
committed the crime than Suspect 2?
a The crime scene sample contains DNA fragments from both the victim and
Suspect 1.
b The crime scene sample contains DNA fragments from both the victim and
Suspect 2.
c Suspect 1 and the victim have more DNA fragments in common that do the
victim and Suspect 2.
d Suspect 2 and the victim have more DNA fragments in common that do the
victim and Suspect 1.
e Suspect 1 and Suspect 2 have more DNA fragments in common than
either have in common with the victim.
4. Why is Suspect 1 considered more likely to have
committed the crime than Suspect 2?
a The crime scene sample contains DNA fragments from both the victim and
Suspect 1.
b The crime scene sample contains DNA fragments from both the victim and
Suspect 2.
c Suspect 1 and the victim have more DNA fragments in common that do the
victim and Suspect 2.
d Suspect 2 and the victim have more DNA fragments in common that do the
victim and Suspect 1.
e Suspect 1 and Suspect 2 have more DNA fragments in common than
either have in common with the victim.
5. In gel electrophoresis, DNA molecules migrate from
_____ to _____ ends of the gel.
a acidic ... basic
b negative ... positive
c basic ... acidic
d long ... short
e positive ... negative
5. In gel electrophoresis, DNA molecules migrate from
_____ to _____ ends of the gel.
a acidic ... basic
b negative ... positive
c basic ... acidic
d long ... short
e positive ... negative
For Thursday
Continue reading chapter 12
More detail on topics covered in Ch 12
For next Tuesday
Remember! Exam #2, Tuesday, 11/6
The exam will cover:
Chapter 6, Cell Respiration
Chapter 7, Photosynthesis
Chapter 12, DNA Technology