bio exam preppp vce Flashcards
RESPECT
informed consent
integrity
being honest and trustworthy
justice
selection of human subjects and non discrimination
beneficence
maximising benefit and minimising harm
non maleficence
do no harm
attenuation
prevents the completion of transcription when trp levels are high and no repressor protein binds onto the operator region
- leader seg to be translated, hairloop pin forms between seg 3 and 4 ribosome detahes stopping transcription
-structural genes not expressed
spacers
segments of dna cut from invading viruses allowing bacteria to recognise the same bacteria in the event of another viral infection
process of obtaining monoclonal antibodies
antigen is injected into mice so they are induced to produce antibodies to specific antigen
antibodies are isolated and fused with tumour cell to form hybridoma
hybridoma is cultured for monoclonal antibodies
monoclonal antibodies used to target defective cells etc
CRISPR CAS9 summary
adaptive immune system of bacteria
virus infects bacteria by injecting its viral dna
spacers sandwiched between the pr and transcribe pre CRrna
crRNA is translated- tracer guide rna
joins w cas 9 endonuclease to cut at a specific recognition site
viral dna disrupted
segment is stored in between spacers.
So. DNA sequence from the bacterial genome transcribed into guide RNA (gRNA).
RNA polymerase uses the DNA sequence as a template to transcribe gRNA with complementary sequence of the spacer and CRISPR segments
The gRNA and cas9 bind form a complex.
It then scans the DNA of any new bacteriophages for the complementary target DNA sequence (to the gRNA).
If present the Cas9 cuts the target DNA.
polyploidy
a change in the no of sets of chromosomes (beneficial one)- plants
aneuploidy
results when homologous chomosoes fail to segregate in anapahse of meiosis stage 1 or when sis chromatids fail to segragate in anaphase of meiosis stage 2, addition and deletion= detrimental
herd immunity
indirect protection of populations from infection. protection is created by vaccinated, unvaccinate receive protection- limits the spread of virus.
herd immunity
indirect protection of populations from infection. protection is created by vaccinated, unvaccinate receive protection- limits the spread of virus.
ELISA
-antibodies attached to test line
- conjugated antibodies are free to move
-when conjugated antibodies bind onto specific antigen- colour change is observed (think rat tests)
steps in allergic response
- allergen
- b cell releases antibodies (iGE)
- iGe attaches itself onto mast cells
histamines released, immune cells attracted
allergic reaction ensues.
gene regulation trp when high
trp binds onto repressor which allosterically modifies it, binds to operator region preventing the transcription.
transcription
-rna polymerase attaches to the promoter region of dna in the upstream region
- unwinds dna exposing the base strand
- rna polymerase moves from upstrem to downstream region (3’ to 5’)
- after rna polymerase moves along dna template, transcription stops and pre-mRNA is released.
translation
mrna moves to the ribosome
reads in triplets
each codon corresponds to anticodon found in trna
- trna brings complementary amino acid to ribosome
- builds a pp chain
once reaching a stop (stop codon) , pp is released from ribosome
post transcription modifications
introns removed
exons spliced
capping of 5’
addition of poly a tail at the 3’ end
vaccine
substance that initiates an immune response
control
used to compare results to
positive control
associated to what is being tested
(expect it to show the expected results of the experiment being tested on)
negative control
is not associated to what is being tested
(expect it to show no results)
PCR
denaturation- heated up to denature double strand to single strand
annealing- cooled down and primers bind on either end of dna of interest
extension- taq polymerase begins amplifying dna at either ends of the primer
recombinant plasmid
endonuclease cuts plasmid at specific recognition site (sticky ends)
same endonuclease is then used to cut dna of interest complementary to the recognition site
mixed and joined together via dna ligase (sticky ends)
purpose of primers
A primer attaches to complementary DNA nucleotides. The addition of the primer and its joining to
complementary nucleotides then allows the DNA polymerase to begin copying. Two primers are
needed as the nucleotide sequence is different at the start and finish of the section of DNA that
must be copied.
physical barrier
physical- intact skin
skin microbiome
mucus
enzymes in tears
ear wax nostril hair
acid envrionment
chemical barrier
sweat mucus tears stomach acid
microbiological
flora
inflammation
vascular stage- chem signals released attract phagocytes, vasodilation, semipermeable and leaky- swelling
cellular stage- phagocyte mugrate to area
-consume bacteria and debris
resolution stage-platelets move- seal wound, abscess forms
structure of antibodies
2 heavy chains, 2 light chains
2 identical specific antigen binding sites
action of antibodies
can bind to antigens to stop them functioning
opsonisation
bind to surface antigens to target them for lysis by complement proteins
species
organism that can interbreed to produce fertile offspring
why use mtDNA?
inherited from the maternal line
non coding region containing d loop
region that undergoes mutational changes at a much higher rate than rest of the molecule
- track human migration over the world
- eacj japlogroup represents diff in mtDNA and allows for the migration of human populations to be tracked out of Africa
trp is high
trp will bind to repressor protein, which allosterically modifies it
the repressor protein will bind onto the operator region
rna polymerase cannot transcribe structural genes
genes not expressed
