keywords:
Bookmark and Share



Front Back
DNA helicase is coded for by what gene? 
dnaB
RNA primer synthesis is goded for by what gene?
dnaG
primer removal; gap filling is completed by what protien, and what gene codes for it?
polA  codes for the DNA Polymerase I
polymerization is completed by which protein, and what gene 2codes for it?
alpha is coded for by the dnaE gene
what protein removes RNA primers, and which gene codes for it? 
RNase H  removes RNA primers and is coded by the gene rnhA
dnaN codes for what protien?
Beta protien, which provides the sliding clamp, which tethers the holoenzyme to the template strand.
which protein, coded for by the gene dnaX, organizes the holoenzyme complex by keeping the leading and lagging strand polymerases together?
T  the tau protein.
RNA primer synthesis is carried out by which protien that is coded by the gene dnaG
primase.
the protein ε,  coded for by dnaQ is responsable for what action durring replication?
5' to 3' editing via exonuclease action
DNA polymerase III completes what function?
doins deoxynucleotides together, to make long chains of dna. 

needs a 3' OH to bind to
termination of replication in E. coli happens at what site?
terA and terB both 22bp long
what enzyme can cause recombination in homologous sequences?
Rec A

but bacteria can resolve dimers back to monomers
resolution of daughter chromosome diamers is controlled by which trans acting functions?
xer A and xer B
where do xer A and xer B act at?
the cis acting dif site of each chromosome
what is the sigma factor in RNA ploymerase used for?
initiation only, it will cycle off after.
what is involved with factor dependent termination of transcription?
the trans acti9ng protein Rho traveles along the mRNA. 
when mRNA reaches the rut site the RNA pol is paused and Rho catches up, momentairly binds in the site. 

dissasociates any RNA-DNA linkages, liberating the strands.
what is an auxotrophic mutant? 
A strain with a mutation in the pathway leading to a biosynthesis or nucleotide biosynthesis or vitamin biosynthesis or a mutaion in a sugar catabolic pathway, or a gene in any part of this pathway. 
what is a good example of an auxotrophic mutant? 
His- auxotropic mutant cannot grow unless the media is supplemented with histadine. 
how would you isolate a resistant organism?   
mutants resistant to a substance (natural or synthetic)  can be isolated by plating the bacteria on media in the presence of that "substance" 
what are some mechanisms for antibiotic resistance? 
membrane permiability

efflux

resistance encoding protein 

spontainious mutations. 
what is a mutation?
a heritable change in the DNA sequence

change is mot repaired

it is relicated
what does it mean if a gene name has a - next to it, as in the case of hisA-
it means there is a mutation in this gene that has inactivated the gene product
what is a conditional lethal mutation?
A mutation that inactivates an essential cellular component, but only under a certain set of circumstances:  for exsample;  a temperature sensitive mutation that inactivates RNA plymerase only at relatively high temperatures or a nonsense mutation that inactivates an essential gene product, but only in the absence of a nonsense suppressor.
how do you isolate a conditional lethal mutant?
in the case of temperature sensative mutants, colonies are grown at permissive temperatures, then moved to non permissive temperatures.  the ones that cannot grow at their non permissive levels are conditional lethal mutants.
resistant mutants
have mutations which cause them to be resistant to a substance (natural or synthetic) 
such as a change in receptors that allow phage to bind, thus rendering the phage inefective
how could you isolate a resistant mutant?
plate them in the presence of whatever "substance"
what does it mean to be "leaky"
in spite of the mutation, the gene product retains some activity.
transitions are when
a base pair change has occured between two purines or two pyrimidines.
transvertions are when
a base pair change has occured between a purine and a pyrimidine.
in a deamination event, what happens when a cytosine is deaminated?
it becomes a uricil, which will then pair with adenine instead of guanine

thisw would be a transition.
x of y cards