Improving food production
- Created by: Buffya
- Created on: 31-05-13 19:34
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- Improving food production
- Microorganisms
- Harmful
- Can spoil food by releasing enzymes to digest it, producing toxins and attacking stomach lining
- Ways to prevent growth
- Irradiation is using ionising radiation to disrupt DNA structure
- Pasteurising - eat to 72C for 15 seconds then cool to 4C
- Salting dehydrates the microgrganism
- Pickling adds acid which denatures enzymes
- Cooling and freezing slows down enzyme activity
- Useful
- Lactobacillus bacteria is used in production of cheese and yoghurt
- Anaerobic respiration is used in bread and in alcohol
- Single cell proteins can be used in the production of food
- Fusariam venenatum is Quorn and a meat substitute
- Grown on any organic substrate
- Advantages are that they contain no animal fat or cholesterol, have a very fast growth rate, have no animal welfare issues and remove waste products
- Disadvantages are that it doesn't have some taste or texture, are grown in an environment where pathogens can also grow and has to be isolated
- Harmful
- Selective breeding
- First isolate the pair of organisms with the desired characteristics
- Artificial selection through the offspring to find those with the best combination
- Inbreeding over generations (controlled)
- Artificial selection through the offspring to find those with the best combination
- We apply selection pressure (not natural selection)
- High milk yield
- Fast growth rates e.g. salmon
- High egg yield
- Marker-assisted selection is when part of the DNA is used to recognise desired characteristics
- Wild tomatoes with resistance to yellow leaf curl virus
- Apples have been bred in this way
- First isolate the pair of organisms with the desired characteristics
- With chemicals
- Fertilisers replace nutrients that previous crops may have removed form the soil
- Pesticides kill organisms that cause disease within crops
- Antibiotics are chemicals that kill or prevent reproduction in bacteria. This reduces spread of disease
- Microorganisms
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