Transcript Chapter 13 Biotechnology 2013

CP BIOTECHNOLOGY
CHAPTER 13
13.1 What is biotechnology?
The use of organisms to
perform practical tasks
for humans
13.1 Biologists Manipulate DNA
 Today,
we mainly manipulate the genomes of
organisms.
 We
called this act of manipulation DNA technology.
13.1 Bacteria – Commonly used in
Biotechnology
* because they can acquire new
genes in many ways!
1. Tunnel-like structure forms
between 2 bacteria so DNA
can be passed-Conjugation
2. Transformation – bacteria
can “take up” free floating
DNA into their own DNA
3. Viruses can carry bacterial
genes from one bacteria to
another- transduction.
13.1 Recombinant DNA Technology
Definition - technology involving the combining of DNA
and/or genes from different sources (even genes
from different species).
Uses of DNA technology:
1.
Make more nutritious crops (ex. Corn)
2.
Make medicine in large quantities
3.
Help us understand specifically how gene sequences
work
13.2 Engineering Bacteria
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Bacteria contain plasmids
Plasmids are small circular pieces of DNA separate
from the bacterial chromosome.
Plasmids carry genes
13.2 Plasmids
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1.
2.
3.
Scientists can manipulate plasmids to make them
useful to us and Bacteria can transfer plasmids!!
Example:
Insert a gene to make a medicine into a plasmid
Put the plasmid into bacteria
When the bacteria reproduce they make many
copies of the medicine!
Process of Making Recombinant Bacterial Cell
13.2 How Do They Do It???
1.
Cut

2.
Paste

3.
4.
Use restriction enzymes to cut the
desired DNA/gene out of a larger
chromosome
Put the desired DNA/gene fragment
into a plasmid
Put the plasmid into a bacterium
As the bacterium reproduces it
makes many copies of the desired
gene!! (Page 270 Case Study)
Restriction
Enzyme=scissors
13.2
Genomic Library & Nucleic Acid Probes
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Genomic Library: the complete
collection of cloned DNA
fragments from an organism
Nucleic Acid Probe:
complimentary nucleotides
labeled with a radioactive
isotope used to “tag” single
strand of a DNA sequence of
choice.
13.2 FYI: Useful Products Using Genetic
Engineering
1.
2.
3.
4.
Bacteria make chemicals that clean up hazardous spills
and toxic waste sites
Bacteria are mass-producing useful chemicals like
pesticides and therapeutic drugs
Pigs & Cattle make human insulin hormone in their milk
for people with diabetes
Recombinant DNA technology is used to develop
Vaccines – Hepatitis B (viral proteins are massed
produced in yeast cells then used in vaccines)
13.3 Genetically Modified Organisms
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A genetically modified organism (GMO) is any
organism that has acquired any genes artificially.
If a species is called TRANSGENIC if it has foreign
genetic material from a different species.
13.3 Genetically Modified Plants
Do you eat genetically modified organisms?
YES
NO
Just a few…GMO FOODS
Honey
 Cotton
 Tomatoes
 Corn
 Vegetable Oil
 Peas
 Potatoes
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Warm-Up - In Groups…
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½ the class will use their books to compile a list of
postive or good reasons/outcomes of using
genetically modified organisms (plants and animals)
½ the class will use their books to make a list of
negative or unwanted reasons to use genetically
modified organisms.
Here’s what YOU think…
13.3 Genetically Modified Plants

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Over 50% of soybean and corn crops were
genetically modified in some way!
Most common genetic modifications:
 Genes
for herbicide resistance
 Genes to resist insect and fungi pests
13.3 Genetically Modified Animals

Goals for GMO animals…
 Produce
mass quantities of hormones (insulin)
 Get animals to market quicker (salmon)
 Breed animals with better quality products (sheep wool)
 FUN!! $$$$$$$
Few more
examples…
13.3 The GMO Controversy
Although studies to date have shown that eating
genetically modified foods have no negative health
affects…people continue to demand stricter
regulations.
Major Concern:
GMO food can pose unknown health risk…request strict
labeling laws
**”ORGANIC CRAZE”**
13.3 GMO Controversy
13.4 DNA Tech Has Many Applications

PCR or Polymerase Chain
Reaction technique can
mass produce specific
sequences of DNA without
the use of living cells
 Takes less time than use
of living cells
 Requires less amount of
desired DNA initially
 Used for cloning rare
DNA & ID small amounts
of infectious DNA (AIDS)
Thermocyclermachine used
for PCR
13.4 PCR Technique
“make a lot of DNA” from a small sample
Page 278 figure 13-15
13.4 Gel Electrophoresis
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Used when you want to compare DNA from
different sources.
Produces “banding patterns” which can be
compared and analyzed.
13.4 Comparing DNA: How it works!
(Pg 279) 1.Different DNA
samples are cut into
“fragments” by
restriction enzymes
2.DNA “fragments” move
through gel using electric
current.
Smaller DNA
fragments
move further
Each sample produces
different banding
patterns in the gel so
they are easily
compared
13.4 Comparing DNA: Genetic Markers

Genetic Markers: are
particular streches of
DN that are variable
among individuals.
 Can
be used to ID
carriers of certain
diseases
13.4 Comparing DNA: DNA Fingerprint
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Just like every person has their own unique
fingerprint…everyone has a unique banding pattern
produced by their restriction fragments in gel
electrophoresis.
97% of our DNA is “junk” or non-coding and is
extremely different from any other persons “junk” DNA.
Forensics!!
13.4 Who committed the crime?
Bloodstain evidence from crime scene!
Suspect #
1 2
3
4
5 6
7
Using PCR and Gel
Electrophoresis, a DNA
fingerprint can be made
from a single drop of blood
or from a hair follicle.
DNA is extracted from a
small sample and
multiple copies are made
using PCR
Gel Electrophoresis of
unique genetic markers are
compared
13.5 Stem Cells and Homeotic Genes
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Stem cells – cells (early in
development) that remain
undifferentiated and have the
potential to be any type of
cell.
Homeotic Genes – genes that
control development of specific
locations in organisms.
Cloning

To make a clone:
A
donor cell is fused with an egg
cell
 The fused cell begins to divide
normally to form an embryo
 Embryo is placed in uterus of foster
mom
 Clone is born
Cloning