Biotechnology

Question 1

Define biotechnology

Answer 1

The industrial use of living organisms (or part of them) for production of: food and drugs

Question 2

Why are microorganisms used in industrial processes?

Answer 2

• Highly versatile; occupying wide range of habitats including extreme conditions
• Rapid growth rate
• Small and can be produced in large numbers in a small volume
• Can be grown in the laboratory so aren’t influenced by climate
• Produce more enzymes per unit mass than larger organisms
• Can be genetically manipulated to express genes for human biochemicals (e.g.)
• Can be manipulated to produce secondary metabolites on demand

Question 3

Define binary fission

Answer 3

The method in which bacteria reproduce and split into 2 asexually

Question 4

Define generation time

Answer 4

The time taken for a bacteria population to double in size

Question 5

Define Lag phase (biotechnology)

Answer 5

• Organisms are adjusting/acclimatising to surrounding conditions and environment
• Cells are active but not reproducing so population remains constant

Question 6

Define Log phase (biotechnology)

Answer 6

• Population size doubles each generation (generation time)
• Reproduction occurs where there is the optimum conditions e.g. abundance of nutrients/food
• Protein/DNA synthesis occurs
• Cell division at its fastest rate
• Some waste toxins begin to build up

Question 7

Define stationary phase

Answer 7

• The death rate= the birth rate so pop. remains constant
• Bacteria have reached carrying capacity which means limited nutrients
• Waste toxins build up more

Question 8

Define carrying capacity

Answer 8

• The maximum number of an organism that can be supported by a habitat
• Is determined by biotic and abiotic limiting factors

Question 9

Define death phase

Answer 9

• Death rate is higher than reproduction

- Toxins are at high level which causes decline

Question 10

What is a fermenter

Answer 10

• An enclosed vessel in which microorganisms are cultured on a large-scale generally
• Must have suitable growing conditions: temp, pH, conc of oxygen, water potential, conc of nutrients and waste products

Question 11

Describe batch cultures

Answer 11

Growth rate is slower because nutrient level declines with time
Easy to set up and maintain
If contamination occurs, only one batch is lost
Less efficient- fermenter is not in operation all of the time
Very useful for processes involving the production of secondary metabolites

Question 12

Give an advantage of batch culture

Answer 12

• Easy to set up and control

- Only 1 batch would be lost if the culture becomes contaminated

Question 13

Give a disadvantage of batch culture

Answer 13

• Have to clean it after every process which takes time
• Expensive; for machinery and labour as need workers to clean fermenter and remove products and change the conditions if a different culture is being used and produced

Question 14

Give 3 uses of micro-organisms in food

Answer 14

o Brewing – yeast
o Mycoproteins – fungal mycelium used to make SCP
o Soya Sauce – fermented soya beans with yeast
o Cheese & Yogurt – Lactobacillus

Question 15

Give 3 uses of micro-organisms in Drugs/Pharmaceuticals

Answer 15

o	Penicillin – Penicillium 
o	Insulin – GM E.coli
o	Enzymes & Chemicals
o	Pectinase – Fungi Aspergillus niger, used for extracting juice from puree 
o	Calcium citrate 
o	Bio-gas

Question 16

Give 3 uses of micro-organisms in Environment

Answer 16

o Sewage
o Waste water treatment
o Organic spills
o Weed control

Question 17

Give 2 uses of micro-organisms in industry

Answer 17

o Biofuels
o Metal extraction
o Plastics production

Question 18

Define primary metabolite

Answer 18

substances produced by an organism as part of its normal growth. Produced in line with growth curve

Question 19

Define secondary metabolite

Answer 19

substances produced by an organism that are not part of its normal growth. Only start to be produced in the stationary phase when nutrients are in short supply and competition is high

Question 20

Give example of primary metabolites

Answer 20

insulin / amino acids / fatty acids / lipids

Question 21

Give an example of secondary metabolites

Answer 21

penicillin

Question 22

Describe continuous cultures

Answer 22

Growth rate is higher as nutrients are continuously added to the fermentation tank
Set up is more difficult, maintenance of required growing conditions can be difficult to achieve
If contamination occurs, huge volumes of product may be lost
More efficient- fermenter operates continuously
Very useful for processes involving the production of primary metabolites