test 3 prep Flashcards
what contributes to the high fidelity of DNA
DNA repair enzymes, base pairing rules, and proofreading capabilities of DNA polymerase III
what does DNA polymerase require to start synthesizing a new strand?
free 3’ end. free template strand. dNTP. Mg++
how can you tell if a baby belongs to a parent by using VNTR?
each VNTR fragment of the child must match one from the parents
what is the relationship between the base sequence of coding strand and base sequence of mRNA?
they are the same, except the thymines are replaced with U’s in RNA
determine size of mRNA- use what technique?
northern blotting
identify a colony from a cDNA library using an antibody?
gene expression screening
identify bacterial colonies who have taken up plasmids via transformation
antibiotic resistance analysis
expression screening
detect protein of interest using antibodies. sticks to tubulin.
Screening via hybridization:
use radioactive probe to identify specific sequences
DNA moves towards (+/-) end
+ end. it’s negatively charged
Southern Blotting
use hybridization to see which fragment in electrophoresis was of interest; identify DNA fragments complimentary to the probe
what do you do if you want to find the size of RNA
northern blotting
antibiotic resistance analysis is used for what process
identifying bacteria colonies that have taken up plasmids via transformation.
in PCR, which end do primers face
3’
steps of PCR
denature, anneal, repeat/extend
Chain termination technique for DNA sequencing
a method of DNA sequencing based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during DNA replication. stops chain, and then you can see where it stopped. how they mapped human genome
what is the blue white test and what is it used for?
screens for plasmids with inserts (inserted DNA sequences)
how would you produce DNA versions of mRNA sequences
cDNA synthesis
discriminate between different allelic forms of B-globin?
RFLP
in blue/white test- what exactly is turning blue? what gene is on/off?
lac Z gene . active lac z=blue, inactive (has plasmid) turns white
relationship cAMP to CAP and what does it do
cAMP binds to CAP in absence of glucose, changing its conformation, so that CAP can bind to activator site
which enzyme turns indicator dye blue?
B-galactoside
how do you turn a tryptophan operon off?
Repressor protein floating around Inactive. When its inactive not bound to operator sequence- RNA polymerase can jump onto promter, transcribe, make mRNA. when tryptophan is present, it plugs into repressor, alters it shape so it can sit down. once its in, RNA can no longer sit there.
tryp operon controlled by ___ protein
repressor
tryp operon is (positive/negative) regulation
negative
given template strand G A T C T G G T, what would be the positions of DNA products using dideoxy ‘A’ DNA?
cuts at : every T, as it forms a complementary A. fragment sizes: 3, 5, 8. 3 fragments.
ascomycete
cup shaped indentations morel
bread mold- type of fungus?
zygomycete
spore print- type of fungus?
basidiomycte
animal-like protists are organized how?
by mode of locomotion
linear fungal growths
hyphae
why is kelp a plant like protists
photosynthetic but no plant-like embryo
leishmaniasis
flagellate pathogen
silent mutation
base change that lets you stay with the same amino acid
how could you produce 5’ sticky ends? give a sequence and what it would turn into
GGATCC
CCTAGG
cut at first G (5’) and last G:
5’ G
3’ CCTAG
mendelson-stahl: F1, F2, and F2 if it had been conservative
F1: middle. a complete mix of parent strands both heavy and light leaves you in the middle
F2: middle, light (semi conservative). half of parental strands are light, half are mixed
F2 if conservative: light, heavy (middle makes one heavy one light)
does every prokaryotic gene have to have an operator sequence? why or why not? give an example of one that doesnt
no. it only needs to have an operator if it has a repressor that needs to be turned on or off.
an example of one that doesnt have an operator is one that’s always on or always off! aka lac repressor structural gene
when would you get a transversion as opposed to a missense, nonsense, etc?
when its an untranslated region
recall that transverion is just a 1 letter switch; aka A to G
is the genetic code universal? why or why not? explain
it’s nearly unviersal- same 4 bases, 3 codon rule for living organisms, 64 options. however , human mitochondrial genes are an exception. also, bacteria use f-met instead of met as a starting codon.
give a sequence for a restriction enzyme recognition site and then cut it to give it blunt ends
5’ TTTAAA
3’ AAATTT
cut down the middle: blunt ends
what do people with zeroderma pigmentosa form?
thymadine dimers
in a bacteriophage- what requirements are needed for properly infecting e-coli?
phage arms + proper central segment
size of genes of interest- hundreds or thousands of nucleotides?
hundreds
how can viruses lead to cancer?
extra copies of oncogenes brought in by a virus
virus could inserts itself into genome, disrupts normal reuglation
screw up signlaing pathway that leads to division- cause abnormal division
how can cell signaling pathways lead to cancer
disrupted pathway can lead to more divison- Many signaling pathways. Many multistep pathways. A mutation in any of these genes would screw up this process.
what does p53 do?
calls in repair enzymes and signals apoptosis. if not fixed, damaged DNA is transcribed and replicated
sequencing your DNA vs a regular cDNA library
1) The cDNA clone will only contain the sequences found in the mRNA, aka NO INTRONS
DNA library = sequence of ENTIRE GENOME
size: cDNA is only a few hundred nucleotides long. DNA library will be 10^5 nucleotides long
what kind of disease is plague
bacterial. usually transmitted by insects or rats
other exampls of bacterial illlnesses
STD’s, legionnaires, tetanus, cholera, lyme
transformed phenotype of cancer cells
de-differentiation
alterd morphology
angiogenesis
chromosomal abnormalities
metasteses
draw a replication bubble with leading and lagging strands
3’ on bottom, 5’ on top. lag bottom left- points in to ORI. then lead bottom right, points out to fork. THEY PINT IN THE SAME WAY. top right: lag, point to ORI. top left: lead, point to fork.
give some examples of transformed phenotype of cancer cells
increased angiogenesis
altered morphology
chromosomal abnormalities (anueploidy)
immortality
de-differentiation
antibiotic resistance analysis
resistance genes are found on plasmids. if bacteria has a plasmid, resists ampicillin. if no plasmid, dies
what do restriction enzymes do that is useful to us
produce genmoic DNA fragments for cloning or screening in a library
what is expression screening
use antibodies to screen gene library
determining size of mRNA
northern blotting
