Biotechnology Flashcards
1
Q
What is biotechnology?
A
Technology based on biology involving the exploitation of living organisms or biological processes to improve agriculture, food science, medicine and industry.
2
Q
What are the 4 main areas that use biotechnology?
A
- Healthcare and medicine.
- Agriculture.
- Industry.
- Food science.
3
Q
What does biotechnology in medicine involve?
A
- Production of drugs.
- Genetic engineering to treat genetic disorders.
4
Q
What are examples if biotechnology in medicine?
A
- Fungus Penicillium cultured industrially to produce penicillin.
- Bacteria (E. Coli) have been genetically engineered to produce human insulin to treat type 1 diabetes.
- Stem cell technology may used to treat a number of different human diseases.
- Genetic engineering may be used to treat a number of different genetic diseases.
5
Q
What does biotechnology in agriculture in involve?
A
- Use of biotechnology to improve crop yield.
- Use of biotechnology to improve animal husbandry and animal production.
6
Q
What are examples of biotechnology in agriculture?
A
- Use of micropropagation to clone plants with desirable traits and improve yield.
- Use of genetic engineering to give plants desirable traits (e.g. Golden rice).
- Use of cloning and IVF to clone animals with desirable traits.
- Use of genetic engineering to give animals desirable traits (e.g. Xenotransplantation and production of pharmaceutical products).
7
Q
What does biotechnology in industry involve?
A
- Using bacteria to produce enzymes and chemicals.
- Use of genetically engineered bacteria to produce chemicals.
8
Q
What are examples of biotechnology in industry?
A
- Fungus A. niger produce and secrete enzyme pectinase, which is vital in juice production.
- A. niger also produces citric acid, which is also used a lot in industry, especially in the food industry.
- Methanogenic bacteria can be used to convert sewage into biofuel.
- Bacteria can be used to breakdown waste in sewage during water treatment.
9
Q
What does biotechnology in food science involve?
A
- Use of biological organisms in the production of food.
- Use of biotechnology to improve the taste, texture, appearance or nutrition value of food.
10
Q
What are examples of biotechnology in food science?
A
- Lactobacillus acts differently on milk depending on different conditions and is used in yoghurt and cheese production.
- Fungus Fusarium used in the production of Quorn.
11
Q
Why are microorganisms often used in biotechnology?
A
- Microorganisms grow very rapidly when conditions are optimum.
- Often secrete many proteins or other chemicals into surrounding where they can be easily collected.
- Can be easily genetically engineered as have relatively simple genomes.
- Can grow regardless of time of year/climate.
- Can grow at relatively low temperatures compared to common chemical processes.
- Products generated are purer than synthetic processes.
- Can grow on and recycle waste/toxic materials.
12
Q
What is a culture?
A
Populations of microorganism/s grown under controlled conditions.
13
Q
What are the stages in a standard growth curve of microorganisms in a closed culture?
A
- Lag phase.
- Exponential (log) phase.
- Stationary phase.
- Death phase.
14
Q
What occurs during the lag phase?
A
- Microorganisms are acclimatising to environment.
- They are carrying out a number of processes before reproduction including:
1. Rehydrating.
2. Growing.
3. Synthesising necessary enzymes.
4 synthesising organelles. - Majority of cells not reproducing, so population size remains fairly constant.
15
Q
What occurs during the exponential phase?
A
- Conditions are optimum and there’s plenty of space and nutrients.
- Cells are reproducing very rapidly.
- Population doubles every generation. Length of time between each generation dependent on organism.
16
Q
What occurs during the stationary phase?
A
- Space and nutrient levels decrease.
- Competition increases.
- Toxic waste products also build up (e.g. CO2).
- Rate of increases and becomes equal to rate of reproduction, so population size remains stationary.
17
Q
What occurs during death phase?
A
- Space and nutrient levels continue to decrease.
- Competition continues to increase.
- Toxic metabolites continue to increase.
- Rate of reproduction continues to decrease and death rate increases.
- Death rate exceeds rate of reproduction, so population begins to decline in size.
17
Q
What is a primary metabolite?
A
Substances produced by an organism that are essential to its growth; including amino acids, proteins, enzymes nucleic acids, ethanol… The production of primary metabolites matches population size.
18
Q
What is a secondary metabolite?
A
Substances produced by an organism that are not essential for growth, but increase its chance of survival. These include antibiotics. There is usually a significant time-lag between population growth and production of the metabolites.
19
Q
What are the factors that need to be controlled during fermentation?
A
- Temperature.
- Availability of nutrients.
- Oxygen concentration.
- pH.
20
Q
Why is temperature important in fermentation?
A
- If temperatures are too low, enzymes don’t work efficiently so rate of population growth and metabolite production is slow.
- If temperatures are too high, enzymes get denatured and the microorganisms get killed.
- Temperature probes and a water jacket maintains optimum temperature in an industrial fermenter to maximise yield.
21
Q
Why is nutrient availability important in fermentation?
A
- Constant availability of nutrients is essential for the microorganisms to keep growing, reproducing and producing desired metabolite.
- Paddles in industrial fermenters constantly stir fermentation medium to ensure organisms are always in contact with fresh medium and has access to nutrients.
- Nutrients are added at regular intervals during continuous fermentation.
22
Q
Why is oxygen concentration important during fermentation?
A
- Industrial processes that require the microorganisms to grow and respire aerobically need to maintain high oxygen concentration by constantly pumping in sterile air and low CO2 concentrations by allowing it to escape.
- This ensures that the microorganisms grow efficiently and don’t produce any unwanted products of anaerobic respiration.
- Industrial processes that require the the microorganisms to respire anaerobically need to ensure that there’s a minimum amount of oxygen present in fermenter, but also allow CO2 to escape, preventing build-up of pressure.
23
Q
Why is pH important in fermentation?
A
- Enzymes have a narrow pH over which they work.
- If pH in fermenter deviates from optimum, enzymes become less efficient.
- Growth and metabolite production becomes less efficient, reducing yield.
- If pH in fermenter deviates too much from optimum, enzymes become denatured and microorganisms die.
- pH probes and buffers are used to maintain constant pH in fermenter.
24
What is the difference between a batch culture and a continuous culture?
- A batch culture is where starter population of microorganisms is mixed with set amount of nutrients in fermenter and left in closed culture. At the end, products are removed and the fermentation vessel emptied to repeat process.
- A continuous culture is when nutrients are added continuously/ at intervals to a population of microorganisms. The desired product is produced and removed continuously.
25
What are the advantages of batch cultures?
- Easy to set up and maintain.
- Contamination only results in small batch being lost.
- Allows for the production of secondary metabolites.
26
What are the advantages of continuous cultures?
- Higher growth rates as there's never shortage of nutirents.
- More efficient due to continuous operation.
- Allows for the efficient production of primary metabolites.
27
What are the disadvantages of batch cultures?
- Growth rate slows down as nutrients are slowly depleted.
| - Less efficient than continuous process as there are time intervals between batches when fermenter not in operation.
28
What is asepsis?
Absence of any unwanted microorganisms in the culture.
29
What are the disadvantages of continuous cultures?
- More difficult to set up and maintain optimum growing environment in fermenter.
- If contamination occurs, large amounts of products are lost.
30
Why is asepsis important in industry?
- Contaminant organisms compete with wanted microorganisms, reducing rate of growth and yield.
- Contaminant organisms may spoil product.
- Toxic chemicals may be produced by contaminant.
- May actively kill cultured microorganism.
31
How can asepsis be achieved in a laboratory?
- Wearing protective clothing, e.g. Gloves...
- Sterilising all apparatus and surfaces coming into contact with microorganism beforehand.
- Working in fume cupboard where good air circulation removes airborne contaminants.
- Minimal contact between apparatus and bench surfaces reduces contamination.
32
Why is asepsis important in the laboratory?
Contamination of a microorganism culture will result in inaccurate results being obtained.
33
How is asepsis achieved in industry?
- Use of steam to disinfect fermenter between batches kills possible contaminants.
- Stainless steel work surfaces ensure no contaminants stick to surface.
- All nutrients are sterilised before adding into fermenter to prevent contamination.
- Air is filtered before pumping into fermenter to prevent airborne contamination.
- All open vents out of fermenter are lined with antiseptic solution.
34
Why are enzymes used in industry?
- Enzymes are more specific, catalysing reactions to produce wanted products and fewer by-products than non-biological processes.
- Enzymes work at a much lower temperatures compared to those used for conventional chemical processes.
35
What are the advantages of immobilised enzymes?
- Enzymes are not present in mixture with product, reducing purification/ downstream processing costs.
- Enzymes can be easily reused so don't have to be replaced.
- More stable and are protected by immobilisation matrix, so are not as easily denatured by high temperatures/ pH.
36
What are the disadvantages of immobilised enzymes?
- Setting up requires more time and materials, so is more expensive.
- Less active due to less exposure to to substrates (no free mixing).
- Contamination requires whole system to be stopped and replaced, which is more costly.
37
What methods are there for immobilising enzymes?
1. Enzyme mixed with adsorption agent (glass beads, clay, resins...) and bind via intermolecular forces. Enzyme weakly bound and leakage is common
2. Enzymes are covalently cross-linked to each other using cross-linking agents (e.g. Gluteraldehyde) and then to insoluble supports (e.g. Clay). Enzymes are strongly bonded, reducing leakage, but only in small amounts.
3. Enzymes are trapped into gel beads or cellulose fibres in their unbound natural states. Rate of reaction reduced as substrates take time to move through entrapment complex and reach enzymes.
4. Enzymes are separated from substate mixture by semi-permeable membrane which allows substrates to diffuse in and products to diffuse out but is impermeable to enzyme, keeping it separate.
