bio chapt 21 biotechnology & genetic modification

• Biotechnology

  The use of living organisms, such as bacteria or yeast, to produce useful substances or carry out processes
• Genetic modification

  Changing the genetic material of an organism by removing, changing or inserting individual genes from another organism
• Microorganisms used in biotechnology

  • Capable of producing complex molecules
  • Reproduce rapidly, meaning the amount of chemicals they can produce can also rapidly increase
• Reasons bacteria are widely used in biotechnology and genetic engineering

  • Lack of ethical concerns over their manipulation and growth
  • Genetic code shared with all other organisms
  • Presence of plasmids
• Uses of bacteria in biotechnology

  • Biofuel
  • Bread making
  • Fruit juice production
  • Biological washing powders
  • Lactose-free milk
  • Penicillin production
• Yeast

  A single-celled fungus that uses sugar as its food source and produces ethanol and carbon dioxide when it respires
• Biofuel production


  1. Plant material chopped up and mixed with yeast

  2. Yeast respires anaerobically and produces ethanol

  3. Liquid separated from solids and water removed, leaving concentrated ethanol
• Biofuel production


  Can cause concern over less land available for local people to grow food crops needed for survival
• Bread making

  1. Yeast mixed with flour and water

  2. Yeast respires anaerobically, producing carbon dioxide

  3. Carbon dioxide caught in dough, causing bread to rise

  
• Fruit juice production

  1. Fruit chopped up and squeezed

  2. Enzyme pectinase added to break down pectin and release more juice

  3. Pectinase breaks down large polysaccharides, making juice clearer
• Biological washing powders

  Contain enzymes that break down large, insoluble molecules like fats and proteins into smaller, soluble ones
• Lactose-free milk

  Milk treated with enzyme lactase to break down lactose, for people who are lactose intolerant
• Penicillin

  First antibiotic discovered, produced by the Penicillium mould
• Penicillin production

  1. Penicillium mould cultured in industrial fermenters

  2. Conditions carefully controlled to produce large quantities of the mould
• Genetic engineering

  Changing the genetic material of an organism by removing, changing or inserting individual genes from another organism
• Recombinant DNA

  The DNA of an organism that now contains DNA from another organism
• Genetically modified organisms

  • Bacteria producing human insulin
  • Crop plants resistant to insects or herbicides
  • Crop plants producing additional vitamins
• Process of genetic modification

  1. Gene to be inserted located in original organism

  2. Restriction enzymes used to isolate gene with 'sticky ends'

  3. Bacterial plasmid cut with same restriction enzyme

  4. Plasmid and gene joined by DNA ligase

  5. Genetically engineered plasmid inserted into bacterial cell

  6. Bacteria reproduce, spreading recombinant plasmid
• Bacteria for genetic engineering

  • Contain same genetic code as organisms genes taken from
  • No ethical concerns over their manipulation and growth
  • Presence of plasmids makes them easy to manipulate

  
• Advantages and disadvantages of GM crops
• Exercise questions