Biotechnology Module 6

Question 1

What is biotechnology?

Answer 1

The use of living organisms in industry

Question 2

Why are microorganisms mainly used in biotechnology?

Answer 2

Their ideal growth conditions can easily be created
Short life cycle so will grow rapidly under correct conditions so products made quickly
Can be grown on a range of inexpensive materials
Can be grown any time of year

Question 3

What enzymes are used in industry called when they are contained within the cells of organisms?

Answer 3

Intracellular enzymes

Question 4

What enzymes are used in industry when they aren’t contained within cells?

Answer 4

Isolated enzymes, some are secreted naturally by microorganisms called extracellular enzymes, but some have to be extracted

Question 5

Why are naturally secreted enzymes cheaper?

Answer 5

It’s expensive to extract enzymes from cells

Question 6

Which microorganism is used in brewing and what does it do?

Answer 6

Yeast, is added to barley and other ingredients.

Yeast respires anaerobically using the glucose from the grain and produces ethanol and CO2, this fermentation

Question 7

Which microorganism is used in baking and what does it do?

Answer 7

Yeast, CO2 made in anaerobic respiration makes the bread rise

Question 8

Which microorganism is used in cheese making?

Answer 8

Rennet, containing the enzyme chymosin which clots the milk

Also lactobacillus and streptococcus which turn lactose into lactic acid turning milk sour and solidifying it

Question 9

Which microorganism is used in yoghurt production?

Answer 9

lactobacillus and streptococcus which turn lactose into lactic acid turning milk sour and solidifying it

Question 10

Which microorganism is used in penicillin production?

Answer 10

Fungi from the penicillium genus produce the antibiotic penicillin to prevent bacteria growing and competing with it for resources

Question 11

Which microorganism is used in insulin production?

Answer 11

Genetically modified bacteria which have had gene for human insulin production inserted into their DNA, insulin is needed for type 1 diabetes treatment

Question 12

What is bioremediation?

Answer 12

Using microorganisms to remove pollutants from contaminated sites

Question 13

Example of microorganism used to make single cell protein which can be eaten?

Answer 13

Fungus used to make Quorn the meat substitute

Question 14

Advantages of producing food for human consumption with microorganisms?

Answer 14

Production of single celled proteins can use waste materials to produce them
Microorganisms can be grown quickly, easily and cheaply. Due to simple growth requirements, less land required and waste products can be used to grow them
Can be cultured anywhere doesn’t matter on environment, so food sources developed in developing countries
Single cell proteins are healthy alternative to meat

Question 15

Disadvantages of producing food for human consumption with microorganisms?

Answer 15

Lots of effort required to prevent contamination, could be dangerous to humans
People may not like idea of eating food produced from waste products
Single cell protein doesn’t have same texture or flavour as real meat
If high quantities of single cell protein meat eaten could lead to health problems due to high levels of uric acid when amino acids are broken down

Question 16

What’s a culture?

Answer 16

Population of one type of microorganism been grown under controlled conditions

Question 17

What are cultures grown in?

Answer 17

Fermentation vessels to collect lots of the microorganism or it’s products

Question 18

What’s batch fermentation?

Answer 18

Microorganisms are grown in individual batches in a fermentation vessel, when one culture ends it’s removed and then a different batch of microorganisms is grown in the vessel

Question 19

What’s continuous fermentation?

Answer 19

microorganisms are continually grown in a fermentation vessel without stopping
Nutrients are put in and waste products are taken out at a constant rate

Question 20

For pH in a fermentation vessel how is it regulated and how does it maximise yield?

Answer 20

pH probe

Allows enzymes to work efficiently, so rate of reaction high as possible

Question 21

For temperature in a fermentation vessel how is it regulated and how does it maximise yield?

Answer 21

Kept constant by a water jacket

Allows enzymes to work efficiently, so rate of reaction high as possible

Question 22

For access to nutrients in a fermentation vessel how is it regulated and how does it maximise yield?

Answer 22

Paddles circulate fresh nutrients around the vessel

Ensures microorganisms always have access to nutrients

Question 23

For concentration of Oxygen in a fermentation vessel how is it regulated and how does it maximise yield?

Answer 23

Strerile air is pumped into vessel when needed

Makes sure microorganisms always have enough oxygen for respiration

Question 24

For sterile conditions in a fermentation vessel how is it regulated and how does it maximise yield?

Answer 24

Superheated steam sterilises the vessel after each use

Kills any unwanted organisms that may compete with ones being cultured

Question 25

In a closed culture what is the standard growth curve?

Answer 25

Lag phase
Exponential phase
Stationary phase
Decline phase

Question 26

Lag phase?

Answer 26

Population size increases slowly, because microorganisms have to make enzymes and other molecules before they can reproduce
Low reproduction rate

Question 27

Exponential phase?

Answer 27

Population size increases quickly because culture conditions are most favourable for reproduction (lots of food and little competition)

Question 28

Stationary phase?

Answer 28

The population size stays level because the death rate is the same as the reproductive rate
Microorganisms are dying because poisonous waste build up and not enough food

Question 29

Decline phase?

Answer 29

Population falls because the death rate higher than reproductive rate because very toxic conditions and very little food

Question 30

How to culture microorganisms in the lab?

Answer 30

Transfer to agar plate using sterile inoculation loop
Incubate plate and allow microorganisms to grow
Nutrients added

Question 31

Aseptic techniques?

Answer 31

Work near a bunsen burner as hot air rises drawing away microrganisms
Sterilise instrument used to transfer microorganisms before and after each use, by passing through a hot bunsen
If using broth, pass neck of bottle though bunsen before and after use aswell
Minimise time agar plate is left open

Question 32

What are immobilised enzymes?

Answer 32

Enzymes that are attached to an insoluble material so they can’t become mixed in with the product

Question 33

What are the 3 main ways to immobilise enzymes?

Answer 33

Encapsulated in jelly like alginate beads, which acts as a semi permeable membrane
Trapped in a silica gel membrane
Covalently bonded to cellulose or collagen fibres

Question 34

Why do immobilised enzymes work?

Answer 34

Active sites are still available to catalyse reaction, but the solution will only contain desired products

Question 35

Advantages of using immobilised enzymes in industry?

Answer 35

Columns of immobilised enzymes can be washed and reused, reducing costs
Product isn’t mixed with enzymes, no money/time used separating them
immobilised are more stable than normal enzymes so less likely to denature

Question 36

Disadvantages of using immobilised enzymes in industry?

Answer 36

Extra expensive equipment needed which is expensive
immobilised enzymes are more expensive to buy than normal ones
immobilisation of enzyme can sometimes lead to a reduction in enzyme activity because not reacting freely with substrate

Question 37

Which immobilised enzyme is used in the Conversion of lactose to glucose and galactose?

Answer 37

immobilised lactase

Question 38

Which immobilised enzyme is used in the Production of semi synthetic penicillins?

Answer 38

immobilised pencillin acylase

Question 39

Which immobilised enzyme is used in Dextrins broken down into glucose?

Answer 39

immobilised glucoamylase

Question 40

Which immobilised enzyme is used in conversion of Glucose to Fructose?

Answer 40

immobilised glucose isomerase

Question 41

Which immobilised enzyme is used in Production of pure samples of L-amino acids?

Answer 41

Immobilised aminoacylase

Question 42

Which immobilised enzyme is used in Conversion of acrlyonitrile to acrylamide?

Answer 42

Immobilised nitrilase