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Key area 3 – Therapeutic
Uses of Cells
National 4
Cell Biology
Uses of cells
Insulin Production
By the end of today you will be
able to:
• Explain that chromosomes in bacteria
are ring shaped and there are other
rings of DNA called plasmids.
• Explain that genes can be transferred
from one living organism to another
allowing bacteria to make new
substances.
• State the advantages and disadvantages
of genetic engineering.
Structure of a typical bacterial
cell
• Here you can see
that bacterial cells
have some of the
structures we have
already seen in
plant and animal
cells.
• These details can
only be seen under
electron microscope
(a very powerful
microscope).
Structure of a typical bacteria
cell membrane
cell wall
plasmid (additional DNA)
Copy the
cytoplasm
diagram into
the space in
your booklet.
main DNA ring
(single chromosome)
flagellum for movement
(not always present)
• The DNA in bacteria is not in a proper nucleus.
• Instead it consists of a main ring or coil of DNA.
• In addition to this, there are other smaller rings of
DNA called plasmids.
• Plasmids are involved in bacterial reproduction.
Answer the questions under the diagram.
Insulin
• Some people need to take insulin every day of
their lives.
• What are these people suffering from?
DIABETES
• Diabetes is a condition where the person’s
body is unable to control their blood sugar
levels properly.
• This is caused by their body failing to
produce enough insulin.
Taking insulin
• Most diabetics need to
take insulin daily.
• This is usually done by
injection.
• Some diabetics have an
insulin pump fitted which
automatically injects the
right amount of insulin
when their blood sugar
level is too high.
• As the human population is
increasing, there are more
and more people who are
diabetic, so more and more
insulin is needed.
Genes and genetic engineering
• Every cell of every living thing contains genes.
• Genes control features and characteristics - a set of
genes is like a set of plans for a living thing.
• Scientists can transfer genes from one living thing to
another.
• This is called “genetic engineering”.
• It is possible to genetically engineer bacteria to get
them to make products they couldn’t make before.
Video clip - Genetic engineering
Let’s be genetic engineers!
(1) Bacterial cell - doesn’t produce insulin.
Genetic material (plasmid)
(3) Seal human gene
into bacterial
plasmid.
Bacterial cell
(2) Insert gene for human
insulin into bacterial plasmid.
Human gene for insulin
(4) “Engineered” bacteria will
multiply and produce insulin,
which can be purified and sold.
Making useful products by
genetic engineering
• Insulin for diabetics is now made using genetic engineering.
• Before genetic engineering was available, diabetics were given
animal insulin extracted from the pancreas of a pig.
• Some people were allergic to this insulin.
• Vegetarians did not want to use it because it came from dead
animals.
• Genetic engineering has solved all these problems.
The pigs might be happy too!
Making useful products by
genetic engineering
• Other useful products
made in the same way
include:
-Factor VIII (Factor 8) –
used to treat people
suffering from a blood
disorder called
haemophilia.
- Human growth hormone
– used to promote growth
in children who do not
grow properly.
Advantages and disadvantages of
genetic engineering
Advantages
• Fast production
• Unlimited quantity can be produced
• Makes a human product instead of an animal product
so avoids allergies
Disadvantages
• Expensive
• Some people think it is unnatural
Stem Cells
Learning Intentions
• Describe what a stem cell is
• State how we use stem cells
• Discuss the dilemmas with stem cell
research and genetic engineering
What are stem cells? - video clip
What are stem cells?
• A stem cell is a body cell that
can develop into any type of
cell.
• Stem cells can divide
repeatedly to form new cells.
• We all have stem cells in our
bodies. They are in many
places, but the most useful
ones are found in our bone
marrow, blood and fatty
tissues.
• Other places scientists can get
stem cells from include
embryos, umbilical cords and
placentas.
Why are stem cells important?
• Scientists look closely at all the genes in these cells to
try and understand why we become ill.
• Stem cells can be used to help treat diseases,
conditions and disabilities.
Using stem cells in the treatment of leukemia (a
form of cancer)
Dilemma!
Vote with your feet!
The following slides contain dilemmas associated
with genetic engineering and stem cell research.
Watch the video clip and then think about the dilemma
shown on the slide.
If you agree with the dilemma
– go to the left side of the class.
If you disagree with the dilemma
– go to the right side of the class.
If you don’t know stand in the middle.
Video clips
Dilemma 1
• Therapeutic stem cells
Dilemma 2
• Designer babies 1 Designer babies 2
Dilemma 3
• Cloning The first human clone?
Dilemma 4
• Saviour siblings
Dilemma 1
Scientists believe they can
come up with a cure for
cancer. However their
research requires using stem
cells from human embryos.
Should scientists be allowed
to take an unborn child's life
for research purposes?
Dilemma 2
Scientists have discovered
the gene that cause a
hereditary disease which
leaves victims in pain
throughout their short life.
Genetic engineering means
that parents can choose the
genetic make up of their
child before
they are conceived.
Should parents be allowed to
have designer babies, so
they can choose their
genetic make up?
Dilemma 3
Cloning intelligent scientists (like Einstein!)
might lead to improved scientific research and
make the other scientists work better (two
heads are better than one?). A cure for cancer
may come sooner if this were the case.
Should human cloning
be allowed?
Dilemma 4
Carrie is 5 and has a medical
condition which means that she
cannot walk very well, is in pain and
is so tired all the time that it is
hard for her to attend school or
lead a normal life.
Carrie’s Mum and Dad know that a
donation of bone marrow from a
close relative could help her.
Nobody in the family is a close
enough match.
They have decided to have another
child by selecting an embryo which
is a match for Carrie.
Should ‘saviour siblings’ be allowed?
Meet Maggie and Jean….
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children needing adopted.