Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

flow of genetic information > DNA replication > Flashcards

DNA replication Flashcards

1
Q

key facts about DNA pol 1

6 points

A 
non replicating
requires all dNTPs
not self priming
5'-3' polymerase
3'-5' exonuclease proof reading
5'-3' exonuclease nick translation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

DNA pol 2 what are the subunits

A

alpha
beta
episilon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do the DNA pol 2 subunits do

and what doesnt it contain

A

A = polymerase
B= clamp (DNA N)
E= 3’ exonuclease proof reading
it does not contain 5’-3’ exonuclease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does DNA pol 2 also form so that we can experiment on them
and what kind of mutants does it form

A

temp sensitive mutants
quick stop
slow stop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when U is incorporated into DNA what is the problem

A

when it is incorporated into GU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

DNA pol 3 what subunits make the active site

what causes dimerisation

A

alpha
epsilon
thi
thi 2 responsible for dimerization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

in pol 3 what clamps the beta clamp whats the loader

A

Y2, sigma2, phi, X

which uses ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

beta clamp what holds it on DNA

A

lysine and argenine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

topoisomerase how many turns for every 10 bp that are replicated

A

1 turn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does topoisomerase do

A

relieves superhelical stress that is produced infront and behind the replication fork

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens to the backbone when topoisomerase binds

A

nicked

and is held together by phosphate tyrosine bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

topo 1 and 3 do what

A

cuts 1 strand
unwinds DNA
decreases L by 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does topo-2 and 4 do

A

cuts both strands
passes 1 strand through another
decreasing L by 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DNA gyrase what does it do

what is its structure

A

uses ATP to decrease L by 2 everytime
A2 B2
tyrosine of A binds to 5’ phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

initiation prokaryotes main points

A

starts at ori c
bidirectionally
has 4 x 9 bp repeats and 3 x 13 bp repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

initiation prokaryotes

DNA A what does it do

A

specific for repliaction initiation
binds cooperatively to 9bp repeats
requires ATP
which interact with 13bp repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

initiation prokaryotes

DNA B what does it do

A

moves along the lagging strand

opening fork

18
Q

initiation prokaryotes

what stabalises the opening of the repliaction fork

A

ss binding proteins

19
Q 
initiation prokaryotes 
DNA G (primase) what does it do
A

associates with DNA B and RNA primer

and the primer is extened by pol 3

20
Q

proof reading how is it done and what happens

A

3’ only proceeds if correct base is added

if not the 3’ exonuclease activity of pol 3 (DNA Q) removes it

21
Q

mechanism of repilaction fork opening

how does it happen

A

DNA B
dna dependent ATPase
1 atp for 3bp unwound
stabilised by ssbp

22
Q

ssbp how are they added

A

as 1 bind the next binds more easily and thus more easily removed

23
Q

synthesis of lagging strand facts

3 sentences

A

even though it is synthesised discontiuously it is made by pol 3
dimer does not dissociate from the DNA template
lagging strand is looped out before synthesis in the 5’-3’

24
Q

ori c a large number of what

and what is it needed for

A

GATC sequences
fo DAM
which immediatley after replication will be hemimethylated

25
Q

DAM

what does it do

A

hemimethylates the DNA

26
Q

termination of replication prokaryotes
what is needed
3 answers

A

6 homologous 23bp sequences
3 sites oriented in each direction
binding to protein TUS

27
Q

what does TUS do

A

prevents fork movement, in only 1 direction

28
Q

termination of replication prokaryotes
what happens to the DNA
how are the chromosomes seporated

A

hemi - DNA at ori c has a stong affinity for cell lipid bilayer
seporated by topo 4

29
Q

replication in eukaryotes
facts
5 facts

A 
does not replicated from a single origin
1000s of replication forks
from ARS
pol is slower
okizaki frags are smaller
30
Q

what is ARS

A

autonomously replicating sequence)

31
Q

eukaryotic pols

5 main types

A 
alpha 
beta
y
sigma 
espilon
32
Q

eukaryotic pols

pol alpha

A

has its own primase activity
not very processive
ass it does not associate with PCNA

33
Q

what is PCNA

A

proliferating cell nuclear antigen

34
Q

enzyme synthesizing the leading and lagging strand dont do what

A

they dont associate as a dimer

35
Q

eukaryotic pols dont have

instead they have

A

5’ exonuclease to remove RNA primer

FEN1 (flap) exonuclease

36
Q

eukaryotic pols

pol sigma does what

A

associates with PCNA and does processive work

37
Q

eukaryotic pols

pol epsilon does what

A 
displaces the primer 
but its not 5'-3' exonuclease
rather then degrading primer
sigma and epsilon writes over it placing it out
FEN1 cuts it out
38
Q

telomers

what are they

A

added repeats at the end of the chromosome

not synthesisted by semi conservative replication

39
Q

telomerase adds telomers
what does it add
what is it

A

it adds repeats of TTAGGG 50-100 bp at 3’ end
ribonucleoprotein
acts as a template for synthesis of telomer repeats

40
Q

how is telomer length regulated

A

by telomer binding proteins

such as TRF1 and TRF2

41
Q

rna replicase

what happens to positive strand

A

+ve strand is replicated directly to make -ve strand
then -ve is used as a template to make +ve
no proof reading

42
Q

reverse transcriptase
what primer is used
how is it degraded

A

tRNA(lys)
rna strand is degraded by RNase H activity
before it synthesises another strand

flow of genetic information (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions