Biotechnology Flashcards
What is biotechnology?
The industrial use of living organisms to produce food, drugs and other products.
Why are microorganisms used?
- Ideal growth environments- as they will grow as long as they have right nutrients, temperature, pH etc
- Short life cycle- products can be made quickly
- grown any time of the year
what does lactic acid bacteria do?
Convert the lactose in milk to lactic acid
- making it sour
What is bioremediation?
Process of using organisms( usually microorganisms) to remove pollutants like oil and pesticides from contaminated sites.
E.g cleaning up oil spills at sea.
What is a single cell protein
protein source that can be used by humans and other animals, grown by use of microorganisms.
Advantages of using microorganisms for the production of food: ( 4 advantages)
1) Waste material (molasses)could be used to make single-cell protein, production of single celled protein could act as a wat of getting rid of waste products.
2) grown quick,easy,cheap- simple growth required, less land required.
3) can be cultured anywhere if you have right equipment, which means a food source can be readily produced in places where growing crops is difficult.
4) Single celled protein considered healthier alternative to animal protein.
Disadvantages of using microorganisms for production of food: (4 disadvatages)
1) food might ger contaminated with unwanted bacteria.
2) people may not like the idea of eating food that has been grown using waste products.
3) Single celled proteins doesn’t have same texture or flavour as real meat
4) If single celled proteins consumed in high quantities, health problems could occur, due to high levels of uric acid released when large amounts of amino acids are broken down.
What is a culture
A population of one type of microorganism that’s been grown under controlled conditions.
Batch femermentation:
Where microorganisms are grown in individual batches in a fermentation vessel, when one culture ends it is taken out and then a different batch of microorganisms is grown in the vessel.
- known as CLOSED CULTURE
Continuous fermentation:
When microorganisms are continually grown in a fermentation vessel without stopping.
- nutrients are put in and waster products are taken out at a constant rate.
What do paddles do in the fermentation vessel?
They circulate fresh nutrient medium around the vessel, making sure microorganisms always have access to nutrients.
What is superheated steam used for in the fermentation vessel?
sterilises vessel after each use
- kills any unwanted microorganisms.
Is the standard growth curve created by batch or continuous fermentation?
Batch
A closed culture is when growth takes place in a vessel that’s isolated from the external environment.
What are the 4 stages of a standard growth curve:
1) lag phase- population size increases slowly
- microorganisms still need to make enzymes needed to reproduce- reproduction rate is slow
2) exponential phase- population size increases quickly because culture conditions are at their most favourable.
Number of microorganisms doubles at regular intervals
3) stationary phase- population size stays level, because death rate= reproductive rate. Microorganisms die because there is not enough food and poisonous waste products build up.
4) Decline phase- population size decreases because death rate is GREATER than reproductive rate because food is scarce and waste products are at toxic levels.
