informatics Flashcards
(14 cards)
biotechnology
change in genetic material and therefore a change in the product of cell during protein synthesis. Extraction of genes from an organism, or the synthesis of genes, in order to place them in another organism (of the same or different species) such that the receiving organism expresses the gene product
Recombinant DNA
the DNA with base sequences that would not normally be present in an organism; this is usually as a result of the introduction of DNA from a different species or individual
Principles of the Polymerase Chain Reaction (PCR)
production of a large number of copies of a length of DNA
Rapid
Only small sample of DNA is required
DNA is denatured (separated into 2 strands with a heat of 95 degrees
DNA primer is added (complementary base pairings begin at the DNA strand)
Annealing 60-65 degrees
Complementary base pairings occur
a type of DNA polymerase called Taq polymerase is added
Replication using template strands 70-75
heated again to separate the strands and the process is repeated
Taq polymerase is stable at high temperatures
does not need replacing
Gel Electrophoresis, used in genetic fingerprinting
People have different VNTR
DNA extracted from a sample
the quantity of DNA increased by PCR
DNA fragmented by restriction enzymes/ endo nuclease
loading into wells in porous agarose gel
at the negative cathode end
buffer solution added to the gel
a direct current is applied across the solution
The phosphate group of the DNA is negatively charged so it is attracted to the positive electrode
shorter pieces/ small masses move faster than larger ones
pieces transferred to absorbent paper after switching current off
they are heated to separate strands
radioactive probes or fluorescent dyes are added
X-ray film or UV light is shined to identify patterns of stripes
Using Bacteria to make human insulin
mRNA extracted from B cells of the islets of Langerhans
mRNA is incubated with enzyme reverse transcriptase
this builds up single-stranded copy DNA which is then converted to double-stranded DNA using DNA polymerase
some single-stranded DNA is added to the ends of the DNA called sticky ends
A plasmid (small circular DNA) is cut open using restriction endonuclease
They cut the plasmids at an angle and to form complementary sticky ends
the cut up plasmids are incubated with the insulin DNA and sticky ends join up complementarily and DNA Ligase joins up nicks in the phosphate backbones
Benefits of plasmids
they are small and can be easily taken up
replicate independently and quickly
have marked genes from resistance/ screening
plasmids can insert themselves into the main loop of DNA and be expressed
they have restriction sites/ can be cut with restriction enzymes
genes enable DNA transfer
how bacteria can be genetically modified and identified using antibiotic resistant genes
recombinant plasmids are mixed with bacteria
some bacteria take up plasmids
heat shock/ ice-cold calcium chloride solution to form pores
to identify bacteria, grow bacteria on an agar culture medium with antibiotic
the plasmid with the resistant gene is injected earlier
bacteria that took up resistant gene survive
use of genes for fluorescent markers in gene tech
they emit bright light
when exposed to UV light
visible colour change
add marker gene to the vector/plasmid
easy to identify bacteria that took up the gene
gene of interest is injected close to the marker gene
no risk of antibiotic resistance
easy to identify the presence of recombinant DNA
vectors
structures transfers DNA into the organism that is to be modified: Plasmids, Viruses, liposomes, agrobacteria
MARKERS
the use of antibiotic resistance genes as markers could increase the likelihood of the development of population of harmful bacteria that become resistant to antibiotics.
Another way of doing it inserting fluorescent gene protein, and cell fluoresce green when exposed under UV light
Bioinformatics
the use of large databases and computer software to store and analyse information about biological (living) organisms in the form of freely available databases
how sequencing of genome and use of bioinformatics can suggest new targets for antimalarial drugs
Identify genes
predict/ primary structure
predict 3D structure/ identify functions of proteins
find drug that can bind and block activity/ disrupt structure of protein/ enzyme
drug can also prevent transcription/ expression of genes
why theoretical model cannot replace
safety
dosage
functionality
advantages of theoretical modeling
cheaper
faster
no need to test on humans
no need for laboratory equipment
