Biotechnology Study

• What process is this?

  Gel electrophoresis (The illustration depicts DNA samples loaded into wells and run through an electric field.)

  
• Which sample/suspect do you think may need further questioning based on the gel?

  Sample A, answers vary, but sample A appears to have the most

  aligned/similar base pair lengths.

  
• Explain the difference between fragment size and distance this graph depicts?

  The larger the DNA fragment size (in base pair), the farther it travels during gel electrophoresis.

  
• What makes an organism transgenic?

  The organisms has had foreign DNA introduced into their genome.
• Transgenesis?


  The transfer of genes from one organism to another can be done in several different ways depending on the organisms.
• Types Of Transgenesis?


  Transformation: Merging DNA of two species using plasmids from bacteria.

  Transduction: Merging DNA of two species using viral vectors. This procedure is the backbone behind gene therapy.

  Transfection: Merging DNA of two animal species using procedures

  such as microinjection or stem cell mediated transfer.
• Name 1-2 ways genetically modified crops can be beneficial?


  The corn allows for less use of pesticides and leads to healthier crop

  production.
• How is Bt corn genetically modified?


  It contains a gene from bacteria that makes it resistant to pests.
• Would Bt corn be considered transgenic?


  Yes
• When was antithrombin approved by the FDA?


  2009
• What is unique about the production of antithrombin?


  Antithrombin was mass produced in goat’s milk using biotechnology.
• How is the gene for human antithrombin

  introduced to goats?


  Via transfection, where the modified human gene is injected into the nucleus of a fertilized goat egg.
• What was the purpose or benefit in producing antithrombin this way?


  Each year, one goat could produce as much antithrombin as 90,000 human blood donations.
• Why is spider silk valuable?


  Spider silk is valuable because it has more tensile strength than steel; it is flexible, and it is lightweight.
• How long did it take to make the silk exhibit found at the New York Museum of Natural History?


  4 years
• Why are the goats transgenic?


  Because they contain gene from another organism that has been put into their chromosomes.
• What do you think the benefit of using goats is?


  The goats can make spider silk faster than spiders, and milking goats is most likely easier than extracting it from spiders.
• Name four ingredients required to make a

  recombinant plasmid (hint: includes enzymes)?


  Gene for insulin from human pancreatic cell, restriction enzymes, plasmid (with antibiotic resistance genes), DNA ligase
• Ampicillin is an antibiotic. The bacteria that have successfully picked up the recombinant plasmid also carry an ampicillin resistant gene on the plasmid.
• How bacteria are selected (how it is determined

  that it has the recombinant plasmid)?


  The bacteria are introduced to ampicillin on an agar plate, if they survive, they have the plasmid and thus the recombinant DNA.
• The First Recombinant DNA:

  Stanley Cohen and Herbert Boyer recombined genes from two different-drug resistant strains of E. Coli. The genes are carried on a plasmid found in E. Coli. They named the plasmids pSC101 (carries gene for tetracylcine resistance) and pSC102 (carries gene for kanamycin resistance).
• EcoR1 is a restriction enzyme that cuts DNA and produces short single stranded sequences called sticky ends.
• DNA ligase is an enzyme that repairs the sugar-phosphate bonds to produce a stable (DNA) molecule.
• How is the “new” DNA molecule different than the original?


  The new E. Coli DNA molecule now contains a gene for both tetracycline resistance and kanamycin resistance.
• How insulin is produced from the bacteria?


  The bacteria are cultured in a fermenter and divide; when the bacteria

  divide, the plasmid does as well. Gene expression is induced, and the polypeptides are created which are used to produce insulin.
• Restriction enzymes are used to cleave the antibiotic resistance gene of interest from a bacterial cell, and then the gene is inserted into a second bacterial cell, and sealed with DNA ligase. If the transformation is successful, the plasmid will now contain a gene for antibiotic resistance.

  
• What is the purpose of the virus in gene therapy?


  The virus is modified with specific DNA and serves as a vector, delivering the new gene into a cell.
• How does the cell respond to gene therapy?


  The cell uses the new gene to make proteins (via central dogma).
• Cystic fibrosis affects the cells of which organs?


  The lungs, pancreas, and small intestine

  The symptoms include coughing, poor digestion, increased vulnerability for infection.
• The DNA genetic code for a healthy CFTR protein?

  ATC ATC TTT GGT GTT
• The mutated genetic code that leads to cystic fibrosis?


  ATC ATC GGT GTT
• What is the function of the healthy CFTR protein?


  Regulates chloride ions across the cell membrane so that water moves out of the cell and into the mucus layer, keeping it moist and able to trap bacteria and debris.
• How gene therapy could treat cystic fibrosis?


  Cystic fibrosis is the result of a mutated gene that does not make healthy copies of the CFTR protein. If a new version of the healthy gene were introduced to a cell, it would theoretically begin making healthy copies of CFTR.
• What CRISPR-Cas9 does within a cell?


  The Cas9 protein seeks out a specific DNA sequence and cuts it at certain point, then new strands of DNA can be inserted or existing DNA can be deleted at that point.
• The final step of CRISPR-Cas9 is DNA Repair. This can be done via non-

  homologous end joining (NHEJ) or homology directed repair (HDR). Which method involves adding new DNA to a strand of DNA?


  Homology Directed Repair (HDR).
• Types Of Biotechnology:

  • Simple: growing mold for penicillin (a natural antibiotic)
  • Advanced: many modern forms of biotechnology involve the manipulation of DNA, known as genetic engineering.
• Biotechnology is the use of an organism to achieve a specific goal.
• Central Dogma (transcription and translation)
• • DNA→RNA →Proteins
• Genes are segments of DNA that code for a specific protein (such as insulin, enzymes, proteins that are fatal to pests and and can act as natural pesticides, etc.)