Biotechnology Flashcards
Describe biotechnology
biotechnology is the alteration of natural biomolecules using science and engineering. it is used to provide useful substances and services
Describe a fermenter
a large vessel used to grow micro-organisms that produce biomolecules
Explain the need to supply suitable conditions in fermenters, and the effect they have on growth rates
a) aseptic precautions - sterilising the fermenter before use and sterilising added nutrients. this stops other micro-organisms that might compete with the type being grown in the fermenter, which would reduce the amount of biomolecules produced
b) nutrients -
c) optimum temperature - probes that monitor conditions in the broth, help maintain optimum temperature for growth of micro-organisms. water jacket removes excess heat generated by reactions in micro-organisms cells as they grow and divide
d) pH - probes that monitor conditions in the broth, help maintain optimum pH for growth of micro-organisms
e) oxygenation -
f) agitation -
Explain the advantages of using micro-organisms for food
production
a) rapid population growth - microorganisms grow and reproduce much more quickly than animals or plants
b) ease of manipulation - microogranisms are easier to handle than whole plants and animals
c) production independent of climate - fermenter need a relatively small area and can be built almost anywhere, while plants and animals need large areas of particular environmental conditions
d) use of waste products from other industrial processes - waste products from other process, such as from making flour, can be used as nutrients for growing microorgnisms - this is cheaper and reduces the amount of waste disposal neede
Describe how mycoprotein is manufactured. describe the process
manufactured using the fungus Fusarium sp. the fungus is grown in large fermenters.
> fungus make makes long thread-like hyphae, which gives mycroprotein a fibrous texture. the broth in the fermenter isn’t stirred as this would damage the hyphae.
Explain the advantages of using mycoprotein as a food source
> contains no saturated fat. saturated fat is a risk factor for heart disease, so health advice is to eat less red meat.
high fibre content, which can reduce the rate of glucose absorption and reduce glucose and insulin surges. also moves intestines faster so carcinogens are removed quickly.
Describe how bacteria are used in the production of yogurt from milk
Fresh milk is warmed to 40 degrees. A culture of bacteria is added to the milk. The bacteria convert lactose in the milk to lactic acid. The lactic acid makes the mixture stet more sour and causes it to thicken.
Describe the use of enzyme technology
> chymosin is a enzyme that affects proteins in milk, making it separate into solid curds and liquid whey. The curse are then used to make cheese. Natural chymosin is extracted from cheese. Natural chymosin is extracted from calves stomachs. The enzyme can be made using genetically modified bacteria , and used to make vegetarian cheese.
invert are converts sugar sucrose into glucose and fructose. Sucrose is commercially produced by yeast. Invertase is used to make the soft centres of some sweets.
washing powders - protease enzymes digest proteins and lipase digest fats and oils. Proteins
Explain recombinant DNA technology using insulin as an
example
1) DNA from a human cell is cut into pieces using enzymes called restriction enzymes. making staggered cuts across the double-stranded DNA, leaving a few unpaired bases at each end, called sticky ends.
2) bacteria cells contain small circles of DNA called plasmids. the same restriction enzymes are used to cut plasmids open, leaving sticky ends with matching sets of unpaired bases
3) the pieces of DNA containing the insulin gene are mixed with the plasmids. the bases in the sticky ends pair up. an enzyme called DNA ligase is added, linking the DNA back into a continuous circle
4) recombinant plasmids are inserted into bacteria. the bacteria can now go be grown in huge fermenter, where they make human insulin
Demonstrate an understanding of the impact of human
population growth on global food security
as human population grows, we need to grow more food so there is enough for everyone
describe the advantages and disadvantages of introducing genes for insect resistance from Bacillus thuringiensis into crop plants
Bt toxin produces a chemical that is poisonous to inspect pests such as caterpillars.
A)
> crop damage is reduced so crop yield should increase
> less chemical insecticide is needed so other, harmless and useful insects are less likely to be harmed
D)
> seed from transgenic plants is more expensive than seed from non-transgenic varieties
> insect pests may become resistant to Bt toxin
> Bt gene may transfer to closely related wild plants by pollination, which would make those plants resistant to pests too
describe the costs and benefits of genetic modification of crop plants in the context of developed and developing countries, including the introduction of flavonoids in the purple tomato
benefits: eating purple tomatoes that contain flavonoids might help anyone with cancer live longer, but they cost more to buy
costs: GM crop seeds may be too expensive for poor farmers
Explain how increased food production for humans includes:
a conventional plant breeding programmes
b pest management strategies
c genetic modification
A) conventional plant breeding programmes:
1) plants with good features are crossed
2) plans grown from seeds of these crosses are selected for their good features and are crossed with each other
3) crossing is repeated many times until a high-yielding variety is produced
B) pest management strategies:
1) increase food production by killing the pests that damage crop plants, these strategies include:
> using chemical pheromone traps to attract and kill pests
> using chemical varieties that are less that are less attractive to pests
> attracting natural predators of the pests
> using chemical pesticides when pest numbers are high
> rotating crops between different fields to prevent a build up of pests in the soil.
a combination of strategies is more useful
describe the advantages and disadvantages of replacing fossil fuels with bio fuels
A) biofuels are renewable, fossil fuels are not crop growth takes carbon dioxide from the air
D) biofuel crops need land to grow on, and this may take land needed for growing food crops
