key area: 2 therapeutic uses of cells unit 1: cell biology

Key Area: 2Therapeutic uses of cells

Unit 1: Cell Biology

Genetic Engineering• What is genetic engineering?

• What is it used for?

National 4 BiologyCell Biology

Genetic Engineering• Watch the following clip on genetic

engineering and answer the following questions.

1. What 3 things are produced by genetically modifying microbes?

2. Name the first organisms to be genetically modified and when this was done?

3. What does insulin normally do? What condition arises from not making insulin?


Click me

http://www.youtube.com/watch?v=zlqD4UWCuws

Genetic Engineering• Genetic engineering means the

manipulation of organisms to make useful products and it has broad applications.

• Genetic engineering has applications in medicine, research, industry and agriculture.

• It can be used on a wide range of plants, animals and microorganisms.


Genetic Engineering• In medicine, genetic engineering has

been used to mass produce insulin, human growth hormone, human albumin, vaccines and many other drugs.

• In research, organisms are genetically engineered to discover the functions of certain genes.


Genetic Engineering• Industrial applications include

transforming microorganisms such as bacteria or yeast with a gene coding for a useful protein.

• Mass quantities of the protein can be produced by growing the transformed organism in bioreactors using fermentation, then purifying the protein.


Genetic Engineering• Genetic engineering is used in

agriculture to create genetically modified crops or genetically modified organisms.


Genetically Modified• A genetically modified organism (GMO) is

one that has been generated through genetic engineering.

• The first GMOs were bacteria in 1973.• GM mice were generated in 1974.• Insulin producing bacteria were

commercialised in 1982.• Genetically modified food has been sold

since 1994


The process of Genetic Engineering

• The normal activities of a bacterium are controlled by its single chromosome and small rings of genes called plasmids.

• In genetic engineering, pieces of chromosomes from a different organism can be inserted into a plasmid.

• This allows the bacteria to make a new substance.



• Collect the diagram and complete the labels.

• Collect the cut out sheet and put the stages of genetic engineering in the correct order.


Uses of bacteria• One of the most common organisms

used in genetic modification are bacteria.

• Bacteria are useful as they are relatively simple to modify, they grow and multiple easily and can quickly produce lots of a particular protein or product.


Uses of genetic engineering• Genetic engineering is used for the

production of substances which used to be both expensive and difficult to produce.

• Examples are: – Insulin for the control of diabetes– Antibiotics such as penicillin– Vaccines for the control of disease– Enzymes for laundry detergents


Uses of genetic engineering• Genetic engineering produces organisms

which have genotypes that are best suited for a particular function.

• Genotype – this is the particular combination of genes expressed by an organism.

• In the past man has used selective breeding to achieve organisms which have genotypes that are best suited for a particular function


Uses of genetic engineering• Genetic engineering has several

advantages over selective breeding.• Particular useful characteristics can

be selected.• The selection may be quicker.• A desirable characteristic can be

transferred from one species to another.


Uses of genetic engineering• As well as bacteria, plants and animals can

also be genetically modified. It is therefore possible to genetically modify people.

• Genetic diseases, such as cystic fibrosis, could possibly be cured this way.

• Genetic engineering could even be used to change physical appearance, metabolism and improve memory and intelligence.

• These uses though are of lower priority to researchers and limited to science fiction.


Issues of genetic engineering• There are dangers associated with genetic

engineering since it creates completely new strains of bacteria.

• It could be possible to create bacteria which are harmful to animal or plant life.

e.g. the gene that gives some plants resistance to weed killers may ‘jump’ to weedsOr the gene carried by viruses into humans may be inserted in the wrong place and cause cancers


Diabetes• 347 million people worldwide have

diabetes (WHO figures for Sep 2012)• Accounts for hundreds of thousands of

deaths each year worldwide• Can cause blindness, kidney failure, need

for amputation, birth defects• Is a risk factor in Heart Disease.


Diabetes - indicators• High levels of blood glucose

(hyperglycaemia)• presence of glucose in the urine

(glycosuria)• increased urinary fluid loss (polyuria)• High levels of ketone bodies in blood• wasting of body mass (due to fat

catabolism)


Diabetes – Task 1• Using the following slide:–Make a table or mind-map to make notes on the two types of diabetes; Type 1 and Type 2 –Try to add no more than 5 key facts on each type and keep the information short and easy to understand!


Diabetes – Type 1• Used to be known as insulin dependent diabetes• Caused by destruction of the pancreas’ insulin-producing β-cells• This causes insulin deficiency• Most frequently emerges in childhood (under 20, average 12

years old) but can present itself at any age• Shows a strong genetic component• Probably triggered by an autoimmune response to something in

the environment (e.g. a virus) that destroys the β-cells’ ability to synthesise insulin

• Patients have an abnormality in glucose homeostasis (i.e. they cannot regulate blood sugar levels)

• Treated with insulin• Symptoms can be relatively severe


Diabetes – Type 2• Typically arise because of insulin resistance (body tissues require greater

than normal insulin for glucose regulation)• Despite sufficient insulin production, adequate glucose does not enter the

cells • The target cells for insulin appear to have a deficiency of insulin receptors• So not enough glucose is taken up into cells such as muscle or liver• Blood glucose levels increase to abnormally high levels• The pancreas tries to compensate by producing more insulin• Eventually the β-cells become worn out and insulin production decreases• Diabetes has developed• Generally occurs among overweight, not very mobile, middle-aged (over

40) individuals with a family history of diabetes – increasing in younger people now!

• Sometimes needs to be treated with insulin but often not• Symptoms can be relatively moderate


Stem Cells• Stem cells are the sites of

production of specialised cells in animals

• They have the potential to become different types of cell.

• Stem cells are involved in growth and repair.


Stem Cells


Stem Cells• Your teacher will

show you a presentation.

• You must take notes from it on stem cells.

• Ask if you need to see it more than once.


Click me

http://outreach.mcb.harvard.edu/animations/thera7c.swf

Growing organs• Organ donation is the donation of

biological tissue or an organ of the human body.

• The demand for organs for transplant far outstrips supply in the UK.

• This means that some patients will not receive an organ in time


Growing organs• In the race to solve the organ shortage,

xenotransplantation has taken place. • This is the replacing of a human organ with an

animal one. • Pigs could potentially provide all the organs that

are required. • Their organs are the right size and they are

already bred in large numbers. • Heart valves from pigs and insulin extracted

from their pancreas have already been used widely.


Growing organs• Why are whole organ transplants

using pig organs not currently offered?

• What problems could there be?• Human immune system doesn’t like

the presence of pig organs and will reject them, concerns over spread of animal diseases to humans.


Growing organs• Much research is now going in to

the use of human stem cells and other organ cells in growing specific organs.

• Currently windpipes have been grown and used.

• Bladders and kidney are currently being grown and the hope is that many more organs will follow.


key area: 2 therapeutic uses of cells unit 1: cell biology

Documents

biology cell biology

stages of genetic engineering

genetic modification

modified organisms

uses of bacteria

produce insulin

useful protein

modified crops