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A2 OCR Biology F215 > Biotechnology > Flashcards

Flashcards in Biotechnology Deck (22):

Define biotechnology

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


Why are microorganisms used in industrial processes?

- 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


Define binary fission

The method in which bacteria reproduce and split into 2 asexually


Define generation time

The time taken for a bacteria population to double in size


Define Lag phase (biotechnology)

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


Define Log phase (biotechnology)

- 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


Define stationary phase

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


Define carrying capacity

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


Define death phase

- Death rate is higher than reproduction
- Toxins are at high level which causes decline


What is a fermenter

- 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


Describe batch cultures

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


Give an advantage of batch culture

- Easy to set up and control
- Only 1 batch would be lost if the culture becomes contaminated


Give a disadvantage of batch culture

- 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


Give 3 uses of micro-organisms in food

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


Give 3 uses of micro-organisms in Drugs/Pharmaceuticals

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


Give 3 uses of micro-organisms in Environment

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


Give 2 uses of micro-organisms in industry

o Biofuels
o Metal extraction
o Plastics production


Define primary metabolite

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


Define secondary metabolite

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


Give example of primary metabolites

insulin / amino acids / fatty acids / lipids


Give an example of secondary metabolites



Describe continuous cultures

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