CHAPTER 20 - Biotechnology and Genetic Modification

• Biotechnology is the use of biology to develop new products, methods, and organisms intended to improve human health and society
• Using microorganisms: Bacteria


  They are small and easy to grow in the lab, they reproduce very quickly, able to make a huge range of chemical substances, and complex molecules that are useful to humans
• Biofuel is a fuel made by mixing ethanol with petrol
• Ethanol is made by the anaerobic respiration of yeast
• Biofuels are good because they are a sustainable resource and release the carbon dioxide that has been stored in the Earth for a long time
• Biofuels are bad because they take up land that can grow food and make it more expensive and the land used contains a biodiverse natural ecosystem but cleared up to grow a monoculture crop
• Pectinase is an enzyme that breaks down pectin
• Biological washing powders contain enzymes that help break down substances that can stain clothes
• Growing microorganisms in a fermenter

  A fermenter is a vessel in which microorganisms can be grown in
• The fermenter is sterilised to kill all the microorganisms in it so it won't contaminate the population of microorganisms growing
• Genetic modification is changing the genetic material by removing, altering or adding individual genes
• Insulin was the first human protein made using GM bacteria to treat diabetes
• 1. The required gene is identified in the human DNA
• 2. Restriction enzymes cut the DNA at specific points, which leaves short lengths of unpaired bases at each end called sticky ends
• 3. Then plasmids are removed from bacteria
• 4. The same restriction enzymes cut the plasmid DNA, so that the plasmid DNA is complementary to the human DNA's sticky ends
• 5. The DNA ligase (ligase enzyme) links the human DNA to the cut plasmid where the plasmid now contains human insulin gene called recombinant plasmid, because it contains a combination of bacterial and human DNA
• 6. The genetically modified plasmids are added to a culture of bacteria which are now also genetically modified because they contain human DNA and their own
• 7. The genetically modified DNA is put into fermenters where they use the code on the human DNA to make the human protein
• Genetic engineering involves altering DNA sequences by inserting new genes into cells using recombinant DNA technology