Biotechnology

  • Biotechnology Today
    • Genetic engineering
    • Manipulation of DNA
  • Bacteria
    • Bacteria review
    • One celled prokaryotes
    • Reproduce by mitosis
      • Binary fission
    • Rapid growth
      • Generation every 20 minutes
    • Dominant form of life on Earth
    • Incredibly diverse
  • Bacterial Genome
    • Single circular chromosome
    • Haploid
    • Naked DNA
      • No histone proteins
  • Transformation
    • Bacteria are opportunists
    • Pick up naked foreign DNA wherever it may be hanging out
      • Have surface transport proteins that are specialized for the uptake of naked DNA
    • Import bits of chromosomes from other bacteria
    • Incorporate DNA bits into their own chromosomes
      • Express new genes
      • Transformation
      • Form of recombination
  • Plasmids
    • Small supplemental circles of DNA
    • 5000-20000 base pairs
    • Self replicating
    • Carry extra genes
    • Genes for antibiotic resistance
    • Can be exchanged between bacteria
    • Rapid evolution
    • Can be imported from environment
  • How can plasmids help us?
    • A way to get genes into bacteria easily
    • Insert new gene into plasmid
    • Insert plasmid into bacteria
      • Vector
    • Bacteria now expresses new gene
      • Bacteria make new protein
  • Biotechnology
    • Plasmids used to interest new genes into bacteria
  • How do we cut DNA?
    • Restriction enzymes
    • Restriction endonucleases
    • Discovered in the 1960s
    • Evolved bacteria to cut up foreign DNA
      • Restrict the action of the attacking organism
      • Protection against viruses and other bacteria
      • Bacteria protect their own DNA by methylation and by not using the base sequences recognized by the enzyme in their own DNA
  • Restriction enzymes
    • Action of enzyme
    • Cut DNA at specific sequences
      • Restriction site
    • Symmetrical palindrome
    • Produces protruding ends
      • Sticky ends
      • Cut other DNA with same enzymes
      • Will bind to any complementary DNA
    • Many different enzymes
    • Named after the organism they were found in
  • Why mix genes together?
    • Gene produces protein in different organism or different individual
  • The code is universal
    • Since all living organisms
    • Use the same DNA
    • Use the same code book
    • Read their genes the same way
  • Copy DNA
    • Transformation
    • Insert recombinant plasmid into bacteria
    • Grow recombinant bacteria in agar cultures
      • Bacteria make lots of copies of plasmid
      • “Cloning” the plasmid
    • Production of many copies of inserted genes
    • Production of “new” protein
      • Transformed phenotype
  • Uses of genetic engineering
    • Genetically modified organisms
    • Enabling plants to produce new proteins
      • Protect crops from insects: BT corn
      • Corn produces a bacterial toxin that kills corn borer
      • Extend growing season: fishberries
      • Strawberries with an anti-freezing gene from flounder
      • Improve quality of food: golden rice
      • Rice producing vitamin A improves nutritional value