What is the molecule of the 21st century?
DNA
GMO stands for
Genetically modified organisms
Who was the first animal to be cloned?
Dolly the sheep, in 1997
Genetic engineering is
the MANIPULATION of DNA
Ligases-
CLOSE (ligates or unite) a fragment of DNA to vector DNA
Restriction endonucleases-
OPEN (cleave or splice) DNA at specific palindromic sequences. fragments can be joined at the sticky ends.
these enzymes are also involved in the inactivation of viral genomes
reverse transcriptase-
converts mRNA into complementary DNA (cDNA) devoid of introns
In SARS, first the RNA is converted to DNA in PCR
What is gel electrophoresis?
the use of electrical current through an agarose gel. DNA that is negatively charged will migrate towards the positive end of the pole. This allows fragments to travel based on their molecular weight. The results are compared to a control.
Describe a gene probe
a segment of DNA or RNA of a known sequence that can base-pair with a stretch of DNA that has a complementary sequence.
short, single strands of 6 to 25 nucleotides called oligonucleotides are used as gene probes
Southern Blot
Separates fragments of DNA using electrophoresis and identifies them using hybridization
Northern blot
Separates fragments of RNA using electrophoresis and identifies them using hybridization
Western blot
Separates fragments of PROTEIN using electrophoresis and identifies them using hybridization
HIV is tested by
using the ELISA test which can give a false positive; using southern blot can be used to confirm.
DNA sequencing is
determination of actual order and types of bases in a 5' to 3' direction in a segment of DNA. Done with 'automatic sequencing machines' (rate of mistakes: 1 in 1000 bases)
Human genome was advanced by who ?
by Francis Collins and Craig Venter in 2001, it took 10 years to develop
There are about ___________ base pairs of DNA code for only about ___________ genes. Humans share _____ of their genome with chimpanzees, _______ with mice, and _______ with rice plants
3.1 billion, 22,000, 90%. 80%, 60%
Human genomes vary only ________ among individuals
0.1%
DNA properties regarding temperature
- high temp (90-95 degrees Celsius) separates the strands, revealing information contained in their bases.
- with the nucleotides exposed, it can be easily identified, replicated, or transcribed.
- when slowly cooled down, nucleotides form to denature the strand
this is the basis for PCR
PCR is
the amplification of fragments of nucleic acids for further analysis, it uses specialized DNA polymerases isolated from thermophilic bacteria (Taq- from Thermus aquaticus)
The steps for PCR are
-Denaturation (@ 94 degrees Celsius)
- priming (annealing) oligonucleotide primers attach at ends of strands to promote replication (@ 50–65 degrees Celsius)
- Extension (@ 72 degrees Celsius) DNAP nucleotides are added to produce 2 complete strands
Most DNA polymerases do NOT survive in
heat
Transfection is
process by which foreign genes are introduced into organisms
Transformation is
forcing DNA into bacteria, can also be done by shotgunning
Genetic engineering is
open policy of sharing to the world
Biotech engineering
make patents, interested in money
Agrobacterium tumefaciums
cancer, tumor in plants
Crown gall is
plant cancer, found on roots
Bacillus therogenesis
killed worms that ate the nodules that produced nitrogen fixation from plants