Friday, December 10, 2010


today we learned how restriction enzymes cut DNA into fragments. Gel electrophore sorts macromolecules by charge and length. DNA fragments have a negative charge and move toward the positive pole smaller fragments move faster than larger ones

Wednesday, December 8, 2010


Genetic Engineering Notes

Today in class we started our notes on Unit 5: "Designer Genes"

DNA Technology- methods to study and manipulate genetic material.
  • corn can produce its own insecticid
  • Bacteria can clean up pollution
  • DNA fingerprints- to solve crimes
  • Advances toward curing fatal genetic diseases
4 Ways DNA technology Can Be Used:
  • Use of recombinant (recombine) to produce useful products
  • Use of DNA fingerprinting in forensic science
  • Comparison of genomes
  • 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.

2. Transduction- the transfer of bacterial genes by a phage. The phage has a fragment of
DNA from its previous host cell. Now it is injected into the new host.

3. Conjugation- a "male" bacterial cell attaches to a "female"v cell by sex pili, a bridge forms, and DNA passes from the male to the female.

Here are some terms we went over today:

Biotechnology- the use of organisms to perform practical tasks.

ex: use of bacteria to produce cancer drugs and pesticides

Genetically Modified organism- an organism that carries recombinant DNA

Transgenic organism- a host that carries DNA from a different species

Cutting and Pasting DNA:

  • Restriction Enzymes- the cutting tools. These enzymes recognize short nucleotide sequences in DNA and cut at specific points.
  • Restriction site- the place where DNA is cut
  • staggered cuts yield 2 double stranded DNA fragments with single stranded "sticky ends"
  • Sticky ends are key to joining with other DNA
  • Join another DNA with 1st DNA
  • DNA ligase connects the DNA pieces
  • Result: a DNA recombinant molecule from 2 different sources

Obtaining the gene of interest: 2 ways

1. Using a radioactive DNA probe
2. Use reverse transcription to make an artificial DNA gene from mRNA

DNA Fingerprinting- a procedure that analyzes a person's unique collection of DNA restriction fragments. Used in forensics- determines whether 2 samples of DNA are from the same individual. Samples come from blood, semen,hair, skin or other biological evidence.

Homework: UP pg. 13-15, 7-10, 5-6

Next scribe: Davin

Wednesday, December 1, 2010

December 1, 2010

Scribe: Katie

  • Notes
  • Lab 37 work
- Review:
  • DNA --> RNA -->Protein
  • Genes determine protein which makes up your appearance and cell capabilities
  • Change in nucleotide sequence of DNA:
a. Base substitutions -replacement of one base for another. Can result in no change, critical, bad or good.
b. Base insertions or deletions - adding or subtracting nucleotides. Often results in disaster- can disrupt entire sequence of triplet pairings.
  • Mutagens - physical and chemical agents, such as UV light, X Rays, chemicals, carcinogens. These CAN cause mutations. They can also lead to diversity. DNA errors can also be due to unknown causes.

Lab info.

  • DNA has two strands, one will have a base sequence.
  • In the process of transcription, a strand of messenger RNA is transcribed with a sequence complimentary to the base sequence of the DNA. (this happens in the nucleus, DNA does not leave the nucleus, RNA does) **Remember RNA has U instead of T-- Uracil instead of Thymine**
  • During translation, codons, or sequences of nucleotides, form a code that specifies the order that amino acids, the "building blocks of protein", should be linked in a protein. Transfer RNA bring amino acids into place to be linked together with the according codons. In this process. the code in the messenger RNA, is translated into a special sequence of amino acids.(This all takes place attached on a ribosome in the cytoplasm)
  • When the ribosome is attached to the messenger RNA, transfer RNA carrying it's specific amino acid molecule, temporarily attached to the messenger RNA at its codon. Then, a transfer RNA molecule complimentary to the adjacent messenger RNA temporarily attaches to it. The ribosome then moves to that point of attachment on the messenger RNA. During each of those attachments, peptide bonds formed between the amino acids. And the transfer RNA molecules become free from the amino acids and RNA, and they can attach to another molecule of it's specific amino acid and carry it to another point along the messenger RNA. This is a growing chain that continues as ribosomes move along messenger RNA, as amino acids are added.
  • This pattern does not end until a termination codon is encountored. This gives the code for the translation to stop.


  • Finish lab 37
  • Do UP pages 99-110
  • Work on Tribune project (Due: 12/7)