Role of Biotechnology (AQA GCSE Biology): Revision Note

Feeding the world population

• Biotechnology involves the alteration and use of living organisms to produce products for human use

• Biotechnology has useful applications for:

  • food production

  • medicine

Culturing microorganisms for food

• Fusarium fungus can be cultured on an industrial scale in order to produce mycoprotein

• Mycoprotein is used in the manufacture of protein-rich meat substitutes, e.g.:

  • vegetarian burgers

  • Quorn^TM

• Fusarium is cultured in fermenters; large vats that provide ideal growing conditions for microorganisms

• Inside a fermenter the fungus is provided with:

  • glucose syrup (and minerals) as its food

  • oxygen for aerobic respiration

  • ideal growing temperatures

  • ideal pH conditions

• The fungal biomass is then harvested (removed from the fermenter) and purified to give mycoprotein

• The fermenter is sterilised before use to kill other microorganisms, which would compete with the Fusarium for food/oxygen, make toxins or be pathogens

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Production of insulin

• Bacterial cells can be genetically engineered, or modified, to produce the human protein insulin

• The modified bacteria can be grown in an industrial fermenter (see above)

• The protein product can then be harvested and purified; the result is medical insulin that can be used in the treatment of diabetes

GM crops

• Crops can be genetically modified (they are known as GM crops)

• Crop plants, such as wheat and maize, have been genetically modified to contain a gene from a bacterium that produces a poison that kills insects, making them resistant to insect pests such as caterpillars. This can improve crop yields

• Crop plants have also been genetically modified to make them resistant to certain herbicides (chemicals that kill plants), meaning that when the herbicide is sprayed on the crop it only kills weeds and does not affect the crop plant, so the crop has less competition for light, water and mineral ions, grows better and gives a higher yield

• Some crops have been genetically modified to produce additional vitamins and improved nutritional value, e.g. ‘golden rice’ contains genes from another plant and a bacterium which make the rice grains produce a chemical that is turned into vitamin A in the human body, which could help prevent deficiency diseases in certain areas of the world

• Some have been genetically modified to be drought-resistant (to grow better in very dry conditions). This can also improve crop yields