Chapter 21: Biotechnology and genetic modification

Question 1

Define biotechnology.

Answer 1

The applications of biological organisms, systems or processes to manufacturing and service industries

Question 3

What does genetic engineering involve?

Answer 3

the transfer of genes from one organism to an unrelated species

Question 4

What do biotechnology and genetic engineering make use of?

Answer 4

bacteria

Question 5

Why is bacteria used in biotechnology and genetic engineering?

Answer 5

1. They have the ability to make complex molecules like proteins
2. Bacterial reproduction under the right conditions occurs rapidly
3. Can be grown and manipulated without raising ethical concerns
4. The genetic code is universal to living things

Question 6

What are plasmids?

Answer 6

Additional DNA molecules which are able to replicate independently of the bacterial DNA

Question 7

How are plasmids used in genetic engineering?

Answer 7

The plasmids are cut open and sections of DNA from other organisms are inserted into them.

When the bacterium divides, the DNA in the modified plasmid is copied, including the ‘foreign’ DNA

Question 8

When do fermentation reactions occur?

Answer 8

When microorganisms take in food and convert it into substances which are useful to them.

The microorganisms also release waste substances like carbon dioxide

Question 9

What microorganism is used in fermentation reactions?

Answer 9

yeast

Question 10

How is alcohol produced?

Answer 10

Yeast converts sugar into alcohol.

Question 11

Tell me the role of anaerobic respiration in yeast during the production of ethanol.

Answer 11

1. Plant material is used as the substrate for producing ethanol.
2. It is chopped up into small pieces and mixed with yeast which respires anaerobically and produced ethanol
3. The liquid is separated from the remaining solids and any water is removed leaving a concentrated solution of ethanol

Question 12

Why isn’t biofuel being used today?

Answer 12

It is not yet economical to produce.

Oil from rapeseed or sunflower seed can replace diesel fuel but is more expensive to produce.

Question 13

Tell me the role of anaerobic respiration in yeast during bread-making.

Answer 13

1. Carbon dioxide make bubbles in the bread dough.
2. These bubbles make the bread ‘light’ in texture
3. Yeast has no enzymes for digesting the starch in flour but the addition of water activates the amylases already present in flour and these digest some of the starch into sugar
4. The yeast then ferments the sugar to alcohol and carbon dioxide
5. The yeast is killed and alcohol evaporates during baking

Question 14

How is pectinase used in fruit juice production?

Answer 14

1. Pectinase works by breaking down a chemical called pectin that is found inside plant cell walls
2. Once pectin is broken down, the cell walls break more easily and more juice can be squeezed out of the fruit
3. Pectinase also helps to produce clearer juice as larger polysaccharides are broken down into smaller molecules, making the juice clearer.

Question 15

How are biological washing powders useful?

Answer 15

1. They contain enzymes that break down and remove stains and greases
2. e.g. proteases carbohydrases, lipases
3. This makes the washing powder more effective than detergent alone especially at lower temperatures
4. This saves energy.
5. The enzyme may not work in acidic/alkaline water or at high temperatures.

Question 16

How is lactose-free mick produced?

Answer 16

Using immobilised lactase enzymes.

The lactase converts the lactose in the milk into glucose and glactose, which are easier to absorb when the milk is consumed.

Question 17

List the key features of the fermenter.

Answer 17

Stream inlet
Nutrient inlet
Water jacket and cooling water
Air inlet
Air inlet filter
Stirring paddles
Probes attached to a computer

Question 18

Tell me the function of the steam inlet.

Answer 18

Hot steam sterilises the inside of the fermenter, ensuring that only penicillium grows

Question 19

Tell me the function of the nutrient inlet.

Answer 19

Introduces sterile nutrients into the fermenter, ensuring growth and reproduction

Question 20

Tell me the function of the water jacket and cooling water

Answer 20

Allows temperature to remain constant. Penicillium has an optimum temperature for maximum growth

Question 21

Tell me the function of the air inlet.

Answer 21

Source of oxygen, provide oxygen for respiration

Question 22

Tell me the function of air inlet filter.

Answer 22

Ensure other microbes are kept out of the fermenter, prevents contamination

Question 23

Tell me the function of the stirring paddles.

Answer 23

Agitates the mixture, ensuring the penicillium and nutrients are combined and prevents hot spots in the mixture

Question 24

Tell me the function of the probes attached to a computer

Answer 24

Monitors temperature and pH, ensures that the penicillium has the optimal temperature and pH for maximum growth

Question 25

How does a fermenter work?

Answer 25

1. Microbes and nutrients are put into the fermenter and air id bubbled through so that the microbes can respire aerobically.
2. As carbon dioxide builds up, the gas outlet releases it to avoid the build-up of pressure.
3. The water jacket surrounding the fermenter maintains the optimum temperature to prevent denaturation
4. Temperature, pH and oxygen probes are linked to a computer which monitors the conditions inside the vessel.
5. Paddle stirrers ensure that the microbes, nutrients and oxygens are well mixed and distribute the heat evenly
6. The product is run off from the bottom. It is separated from the microbes and purified so that it can be sold or distributed.

Question 26

What is genetic engineering?

Answer 26

Changing the genetic material of an organism by removing, changing or inserting individual genes.

Question 27

Why are organisms genetically modified?

Answer 27

To give them a combination of genes that will result in them having desirable physical characteristics

Question 28

Describe the process of genetic modification.

Answer 28

Question 29

List the advantages of genetically engineered insulin.

Answer 29

1. Mot limited by the slaughter of animals
2. Large quantities can be made quickly
3. No risk of transferring infections
4. More effective at treating diabetes as animal insulin is different to human insulin
5. No ethical issues concerning the use of animals

Question 30

Tell me the advantages of golden rice.

Answer 30

Produces beta-carotene, needed by humans and used to make vitamin A.

Used in areas where vitamin A deficiency is common, so helping to prevent night-blindness.

Question 31

Tell me the disadvantages of golden rice.

Answer 31

Beta-carotene levels in the golden rice may not be high enough to make a difference

This is potential for cross-breeding with and contamination of wild rice

Concerns around human safety

The seed for GM plants can be expensive

Question 32

What are the advantages of growing soya and maize?

Answer 32

Pesticides and herbicides can be added to a field without harming the crop

Fewer insecticides and pesticides have to be used

Higher crop yields

Question 33

What are the disadvantages of growing soya and maize?

Answer 33

Pesticide and herbicide residues or substances can cause allergies

Loss of biodiversity because fewer weeds survive-resulting in reduced food and shelter for animals

The potential development of herbicide-resistant weeds.

Pesticide could kill harmless or even helpful insects like pollinators.