Wednesday, December 7, 2011

Wednesday, December 7

Today in class we finished up the video that we watched yesterday. We also received a new and updated calendar because the last one was messed up. Still use the Google Doc to make sure that you do the right homework.

For the bulk of class today we started the Genetic Engineering note packet. Here is what we got done today:

DNA Technology: methods to study and manipulate genetic material.
  • Corn can produce its own insecticide.
  • Bacteria can clean up pollution
  • DNA fingerprints-to solve crimes. Anything that is cellular has a DNA fingerprint. It's not your fingerprint on your finger.
  • Advances toward curing fatal genetic diseases. (Ethical Problems?)
Human Genome Project
  • To sequence all DNA in the human genome
  • To identify location and function of every gene.
  • 2003-99% sequenced
  • Hundreds of disease-associated genes identified
  • Ex: Parkinson's Disease
4 Ways DNA Technology Can be Used
  1. Use of recombinant (recombined or changed) DNA to produce useful products.
  2. Use of DNA fingerprinting in forensic science
  3. Comparison of genomes
  4. Use of human gene therapy for treatment of diseases
3 Ways to Transfer DNA
  1. Transformation-the taking up of DNA from the fluid surrounding a cell. Ex: 1920's-Griffith-a harmless strain of bacteria took up pieces of DNA left from dead cells of a disease-causing strain.
  2. Transduction-the transfer of bacterial genes by a plasmid (circular piece of DNA in bacteria). The phage (virus) has a fragment of DNA from its previous host cell (a stowaway). Now it is injected into the new host.
  3. Conjugation-a "male" bacterial cell attaches to a "female" cell by sex pilli, a bridge forms, and DNA passes from the "male" to the "female."

  • Once DNA gets into a bacterial cell, by whatever method, it can integrate into recipient's chromosome, replacing part of the original DNA
  • Some plasmids can transfer a copy of themselves to another cell by conjugation

Recombinant DNA Technology-lab techniques for combining genes from different sources & species into a single DNA molecule.
  • Biotechnology-the use of organisms to perform practical tasks
  • Ex: Use of bacteria to produce cancer drugs & pesticides
  • Ex: Transfer of genes into plants and farm animals
More on biotechnology
  • Genetically modified organism (GM or GMO)=an organism that carries recombinant DNA
  • Transgenic organism=a host that carries DNA from a different species
  • Through biotechnology-can make Humulin, human insulin, made in bacteria. 1st recombinant DNA drug for human use in 1982.
  • Genentech Biotech Co.-knew amino acid sequence of the human insulin protein. Put the DNA sequence together, inserted them into E. Coli cells. Bacteria cranked out large quantities of insulin.
  • Produced in fermentation vats, 4 stories high, 24 hrs/day.
  • 4mill.+ people with diabetes use this.
  • Human Growth Hormone-used to come from human cadavers (dead people). Now grown in transgenic bacteria.
  • Erythropoietin (EPO)-mammalian cells grow this protein, a treatment for anemia. (Anemia is when you have blood with low amounts of iron in it)
  • For vaccines-genetically engineered cells make large amounts of the antigen on the pathogen. Ex: Yeast produces a vaccine against hepatitis B, a liver disease.
  • In 2002 1/2 of American crops of soybeans and corn were genetically modified
  • Corn-resists attack from European corn borer
  • Strawberries-bacterial proteins act as natural antifreeze
  • Potatoes-provide cholera immunity
  • Golden rice-with beta-carotene which body uses to make Vitamin A
  • Transgenic sheep-carry human gene in milk, used for treatment of cystic fibrosis
  • No transgenic animals used in food supply yet. Ideas: Leaner meat, faster maturing cow, larger muscles on cattle.
  • Ethical problems? Safety problems?
Recombinant DNA Techniques
  • use bacterial plasmids: they are small and readily taken up by bacterial cells. Act as vectors, carriers that move genes from one cell to another. Replicates any foreign DNA that has been inserted.
That is all the notes we got through today in class.
HW Tonight: UP pages 7-10, try pages 13-15. MEET IN SCIENCE COMPUTER LAB TOMORROW.

Next scribe: Jimmy

Tuesday, December 6, 2011

Today we started a new unit. Mrs. Andrews advised that we do not follow the calender she gave us, rather we follow the google docs because the calender has some errors. Due to the fact we had a shorten class period, we watched a movie on the murder of two teenagers.

On November 21st, 1983 a crime occurred in a small town in England. A teenager named Lynda was killed. She was actually sexual assaulted, strangled, and raped. Detectives spent many years trying to find the killer of this case, but nothing was drawn except the fact that the killer's blood type of was AB. Three years later in the same town, a 15 year old girl, Dawn went missing. She was later found strangled and sexual assaulted. Dawn's and Lynda's case had similarities because they were both sexually assaulted at the same place, thus they were both teenagers. Eventually a prime suspect, Richard Buckmenth, confessed of killing Dawn but not Lynda. Blood types of the Dawn's case was taken to the University of Leichester and there a member of the RFLP, Allec Jeffreys, used DNA in a murder case. He used the small part of DNA and used restriction enzymes to cut the DNA. This way the person can be figured out using DNA. It turned out, Richard's did DNA did not match the one of the real killer. Soon he was released. Allec figured that the killer had killed both Dawn and Lynda. Therefore the police sent letters for a voluntary blood test. They wanted to match the blood type of AB. A bakery owner, Colin Pitchfork, did not attend because he did not want to deal with the police again. So instead he made his friend, Eion Kelly take it by replacing his passport picture with Eion's. Eventually Eion was bragging about what he did and a lady overheard and told the police. The police eventually heard about this and soon he confessed he was the killer for both girls. All evidence, including the DNA, of this matched.

On the right is Colin Pitchfork and on the left is Lynda Mann.

Homework: Take notes on pages 200 and 208-211, UP 5-6

the next scribe is Jackson!