STS 21 - GENETIC ENGINEERING

• Genetic Engineering


  DNA of an organism is altered or modified to create a new organism
• Recombinant DNA technology


  Used to alter the genetic makeup of an organism
• Gene splicing


  Other term aside from recombinant DNA and genetic modification
• Genetic modification


  Altering the genetic makeup of an organism
• Genetic engineering is possible because the genetic code is universal- all living things have: A (adenine), T (thymine), C (cytosine), and G (guanine) in their DNA
• Enzymes needed for Genetic Engineering

  • Restriction Enzyme
  • Ligase
• 6 Stages in Genetic Engineering

  1. Restriction enzyme cuts the DNA into Fragments

  2. DNA from another organism is cut using the same enzyme

  3. Two fragments stick together by complimentary base pairing

  4. DNA ligase pastes or glues the sugar phosphate backbones

  5. Production of recombinant DNA molecule
• Complimentary base pairing means that the DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine
• As a result of Genetic Engineering, bacterial cells can be "factories" that produce human insulin for diabetics
• Bacterium

  • Relative ease of modifying their chromosomes
  • Unicellular and reproduce asexually making them replicate faster
  • Have plasmids, small circular pieces of DNA, used to reproduce recombinant DNA
• How human insulin is created

  Bacterial cells are used as "factories" to produce human insulin
• Roles of GMOs according to the Center for Ecogenetics and Environmental Health (CEEH, 2013)

  • Pest resistance
  • Virus resistance
  • Herbicide tolerance
  • Fortification
  • Cosmetic preservation
  • Increased growth rate
• Pest resistance


  • Bt Corn. The DNA of the corn has been modified with the gene of Bacillus Thuringiensis, a soil bacterium that produces proteins which is toxic to corn borers (worms)
• Virus resistance


  • Papaya ring spot virus (PRSV). The protein of PRSV was introduced to papaya plant through plant tissues which tuned out to resistant to the virus itself
• Herbicide tolerance


  • Roundup Ready soybean. Glyphosphate, an herbicide for weeds, was introduced to soybeans making it tolerant to the herbicide itself
• Fortification


  • Golden Rice. Beta- carotene, a precursor of Vitamin A, was introduced through biosynthesis genes to the rice, making the rice grains fortified with vitamin A
• Cosmetic preservation


  • Arctic Apple. They are genetically modified to suppress the browning of apple due to the superficial damage
• Increased growth rate


  • Aqua Advantage salmon. A gene from ocean, an eel- like fish was introduced to Pacific Chinook salmon, making the salmon grow faster than its normal rate
• GMOs in Non-Food Crops and Microorganisms

  • Paper production
  • Pharmaceutical production
  • Bioremediation
  • Enzyme and drug production
  • GMOs in the Medical Field
• Paper production


  • Poplar trees. Modified characteristics of trees for higher yield of paper production
• Pharmaceutical production


  • Periwinkle plants. Modified plants to produce pharmaceutical products
• Bioremediation


  • Shrub Tobacco. Use of modified plants that can assist in the bioremediation of polluted sites
• Enzyme and drug production


  • Use of modified microorganisms that can produce enzymes for food processing and medicines
• GMOs in the Medical Field


  • Humulin. Modified to produce human insulin
• Benefits of GMOs


  • Higher efficiency in farming
  • Increase in harvest
  • Control in fertility
  • Increase in food processing
  • Improvement of desirable characteristics
  • Nutritional and pharmaceutical enhancement
  • Reduce the use of fertilizer and pesticides
• Potential Risks of GMOs

  • Inadequate studies on the effects to humans and the environment
  • GMOs promote mutation in organisms, long term effects are unknown
  • Human Consumption: More allergic Reactions, Gene Mutation, Antibiotic resistance, Nutritional Value
• Potential Environmental Risks of GMOs

  • Risk in gene flow
  • Emergence of new forms of resistance and secondary pests and weed problems
  • Recombination of virus and bacteria to produce new pathogens
• Potential Health Risks of GMOs

  • May have an adverse effects because it is not naturally or organically produced
  • May alter the balance of existing microorganisms in the human digestive system
  • May produce toxins
  • Production of allergies may have adverse effects on Humans
• What are the four genetic code in universal things?

  Adenine, Thymine, Guanine, Cytosine
• Gene Therapy


  Designed to introduce genetic material into cells to compensate for abnormal genes or to make a beneficial protein
• Gene Therapy

  1. Replacing a mutated gene that causes disease with a healthy copy of the gene

  2. Inactivating, or "knocking out," a mutated gene that is functioning improperly

  3. Introducing a new gene into the body to help fight a disease
• If a mutated gene causes a necessary protein to be faulty or missing, gene therapy may be able to introduce a normal copy of the gene to restore the function of the protein