Download Biotechnology

Unit 6
BIOTECHNOLOGY
Maury
 http://www.youtube.com/watch?v=ZD78-
CCPhAQ
 What did they do to tell who the father was?
 How do they do these tests?
 How do they know for SURE?
What is biotechnology?
 Bio = Life
 Technology = machinery, equipment, or the
application of knowledge
  Technology that relates to the field of
biology or living things
 Manipulating living organisms using various
types of technology to produce more useful
qualities  using better genes and traits
 Allows the best or desired traits to be
expressed.
Research in Biotechnology
Help humans create crops that can be frost
resistant
2. Use transgenic organisms to help medical
researchers model human physiology for
testing
3. Help industries to create bacteria to break
down pollutants into harmless products
4. Pharmaceutical companies use recombinant
DNA to cheaply produce human hormones
(insulin) and other proteins
5. Help solve crimes and determine familial
relationships
1.
Gel Electrophoresis
 A method used in biochemistry and
molecular biology to separate DNA or RNA
molecules by size to compare DNA data.
 Also called a “DNA fingerprint”
 Unique to each person
What can this be used for?
 Paternity Tests
 Who is the father?
 Familial Relationships
 Who is the mother?
 Who are the siblings, cousins, grandparents, etc.?
 Evolutionary Relationships
 How closely related are two organisms (humans & apes)?
 Crime Scene Investigations
 Who committed the crime?
Basic Steps..
1. Extract DNA sample
2. Cut DNA into smaller pieces using Restriction
Enzymes
3. Put the smaller DNA fragments into the Gel Tray
4. Use an electric charge to separate the pieces of
DNA
5. Analyze the DNA fragments
Goal of Gel Electrophoresis
1. The process of Gel Electrophoresis works to
separate and analyze DNA fragments
according to their size & shape.
2. In order to cut the DNA into fragments,
restriction enzymes are used.
 These are specific enzymes (proteins) that
recognize specific sequences of DNA and then cut
it in half.
3. Samples of DNA fragments are loaded onto a
GEL ELECTROPHORESIS.
4. DNA fragments move in the Gel due to opposite
charges (DNA is negatively charged)
 The SMALL strands move further down the Gel than
the LARGER strands of DNA.
 Since they are larger and heavier, the LARGER
strands do not move as far down the Gel
5. The groups of DNA fragments show up as
small lines in the Gel
6. Now a DNA FINGERPRINT is created, which
can be analyzed.
Let’s Take a look…
 http://www.youtube.com/watch?v=PSwlCk_Z
02c&feature=related
Check Point
1. What are the steps used in Gel electrophoresis?
2. Where would you find the shortest stand of
DNA?
3. What causes the fragments on DNA to move?
DNA fingerprinting
applications
Sample Problems
Genetic Engineering –
Transgenic Organisms
 What is a transgenic organism?
 Let’s break down the word…
 Trans = across
 Genic = genes
 Organism = Living thing
 Transgenic Organisms are:
 It is an organism that has had genes inserted (or
moved into) from a different organism
 Transgenic organisms are made from combining
different DNA
Genetically Modified Food
(GMO)
Genetically Modified Food
(GMO)
What is Genetically Modified
Food (GMO)?
 It is a crop or food that has been intentionally
modified, altered or changed.
What is Selective Breeding…
 A type of genetic engineering
 Choosing organisms (plants, animals) with
the best traits (genes) and breeding them
together to produce better (bigger, stronger)
offspring
Can you thinks of a real life
example of selective breeding?
How did THIS happen?!
Glow-in-the-dark PIGS?!
 A desired gene from one organism (the glow
gene from a fire fly) was inserted into the
DNA of a pig
 Through MITOSIS the pig’s cells began
replicating the glow-in-the-dark gene (the
desired gene)
 Let’s take a closer look at this…
What is Recombinant DNA
 When DNA from two different organisms
come together, the DNA becomes
RECOMBINANT DNA
 What does recombinant (recombine) mean?
• The organism that receives the
recombinant DNA will use it as if it were
its own DNA.
Also know as…
 Transgenic Organisms
How do scientists create
DNA?
 Its all about using BACTERIA!
 This is because bacteria have DNA rings
called PLASMIDS.
Steps for Creating a Transgenic
Organism
1. Remove the plasmid
2. Cut the bacterial DNA using restriction enzymes,
3.
4.
5.
6.
leaving an open “sticky end.”
Remove and cut a desired gene from a different
organisms (foreign DNA), also leaving an open “sticky
end.”
Then glue a piece of foreign (human, plant, animal)
DNA back into the plasmid using the enzyme Ligase
and sticking the “sticky ends” together.
Insert the plasmid back into the Bacteria
Now, the bacteria will reproduce the new gene (in the
plasmid DNA) to make larger quantities of the desired
gene or trait.
All bacteria are…
 IDENTICAL
 REMEMBER: bacteria divide using asexual
reproduction!
 SO…
Every new bacteria will be making exact copies of
the desired gene!
Applications of Recombinant
DNA
 Bacteria
 used to produce hormones,
antibiotics and Insulin
 Plants
 made to be resistant to herbicides
and Pesticides
 Animals
 Cloning
 Replacement of genes which cause
disorders (aka Gene Therapy)
 Such as Cystic Fibrosis
 Severe Combined Immunodeficiency
Check Point 1
1. What is a Transgenic Organism?
2. How are transgenic organisms made?
3. What is a GMO?
4. What is a real-life example of a GMO?
5. What is selective breeding?
6. What is a real-life example of selective
breeding?
Human Genome Project
 A collaborative effort by scientists around the
world to map the human genome
 Genome = all of an organism’s hereditary
information
 Completed in 2003
 Can be used to determine if people carry
genes for certain traits or diseases
 Can be used to determine the locations of
genes on chromosomes
Problems with the Human
Genome Project:
 What do we do with the information?
 Designer babies?
 Abortion of defective babies?
 Sterilize carriers?
 Will insurance companies be able to deny you
coverage because of your genes?
 Can pharmaceutical companies “copyright” a
gene sequence?
 If so, what happens to people with that gene?
 http://www.youtube.com/watch?v=XuUpnAz5y1g&feature=related
Cloning
 A clone is an organism that is a perfect copy
of another organism
 Clones can happen in nature
 Identical twins
 Some organisms (like bacteria) “clone”
themselves through asexual reproduction
Cloning
 Cloning mammals is really hard  we used to
think it was impossible
 Dolly the sheep – 1996
Making a Clone:
 1. A cell is taken from the donor.
 2. An egg is taken from another adult animal.
 3. The egg has all of its genetic material (DNA)
removed.
 4. The genetic material (DNA) is taken from the
donor cell and placed into the now-empty egg.
 5. The egg with the donor’s genetic material is
placed in a foster mother where it will divide
and grow into a baby. This is the clone, a
perfect copy of the original donor.
Problems with Cloning:
 Most attempts to clone have failed
 Of the attempts that succeed, most have
health problems
 Large offspring syndrome (LOS) – clone
babies tend to be larger than other babies of
their species  the enlarged organs cause
health problems
 Gene expression – a clone may not express
the same genes as the original, even if they
are genetically identical
Problems with Cloning
 Clones tend to have weak immune systems
 they are more vulnerable to disease
 Cells tend to have more trouble dividing
properly the older an organism is  if you
take an “old” cell from an older organism and
grow a younger organism (clone) from it,
there will be even more dividing problems
 Therefore, it is currently illegal to clone
humans in the United States
What is Gene Therapy?
 The transplantation of normal genes into
cells in place of missing or defective ones in
order to correct genetic disorders.
Gene Therapy
 Still in the theory/testing stages
 1. A person is tested for faulty genes
 2. A person with a healthy copy of the gene donates
some cells and has the healthy copy cut out using
restriction enzymes
 3. The healthy copy is loaded into a vector (carrier),
usually a virus.
 4. The sick person is infected with the virus, which
will inject the gene into their cells, hopefully
“patching up” the problem.
 http://www.youtube.com/watch?v=CkWep1Z0gCw
Diseases that can be cured
with Gene Therapy
 1. Cystic fibrosis = causes respiratory tract to
produce a thick mucus (instead of the normal
thin, watery kind) that can clog passageways
and lead to suffocation. People with CF
usually die by 30
 2. Severe Combined Immunodeficiency
(SCID) = affects two kinds of infection
fighting cells, leaving patients susceptible to
diseases. Women are usually only carriers,
men are usually the ones affected.
Problems with Gene Therapy
 Very expensive to research and test
 We don’t know what the side effects will be
 We still don’t understand everything about
genes  how do we know this will fix the
problem?
Stem Cell Research
 Stem cells are a “blank slate”  they can
become any kind of cell through
differentiation  ex. Heart cell, lung cell
 Two main kinds:
 Adult stem cells = come from adults
 Embryonic stem cells = come from embryos
grown in the lab
Stem Cell Research
 Scientists prefer to work with embryonic
stem cells
 Easier to identify, isolate, and harvest
 More of them than adult stem cells
 Grow more quickly and easily
 Easier to manipulate
Problems with Stem Cell
Research
 Financial
 It is very expensive
 Ethical
 Destroying embryos
 Stem cells can cause cancer if they divide out of
control
 Why use embryonic when adult cells are available?
 Adult stem cells avoid problem of immune
rejection