Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > New: DNA Replication > Flashcards

New: DNA Replication Flashcards

1
Q

which phase of the cell cycle does DNA replicate?

A

S phase

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

Semiconservative replication was first suggested by who

A

watson and crick

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

3 models of replication

A

conservative; dispersive; semiconservative

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

conservative model of replication

A

old duplex is conserved and new duplex composed of to completely new strands

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

dispersive model of replication

A

sections of the old duplex dispersed somewhat randomly to the two daughter strands

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

semiconservative model of replication

A

two daughter duplexed with one each of the old and new strands

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

the ____ of DNA contain ___

A

bases; nitrogen

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

Matthew Meselson and Franklin Stahl used what in their experiment

A

E. coli; naturally occurring N14 and heavy N15 isotopes of nitrogen; ultracentrifuge; pulse-chase experiments

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

isopycnic

A

equal density

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

Meselson-Stahl explanation

A

first generation results eliminated conservative model (after 1 generation DNA contained 50/50 N15 and N14)

second generation results eliminated dispersive model

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

DNA replication occurs in a

A

semi-conservative manner

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

Each strand of DNA acts as a

A

template for synthesis of a new strand

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

Daughter DNA contains one parental and one

A

newly synthesized strand

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

three stages of DNA replication

A

initiation; elongation; termination

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

much of what we know about DNA replication is because of

A

E. coli

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

DNA replication must be ____ and _____

A

rapid and accurate - mistakes can be lethal

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

___ and ____ play a role in keeping DNA replication accurate

A

repair and recombination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

DNA is replicated by

A

polymerases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

which polymerases play a key role in DNA replication

A

1 and 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

DNA polymerase catalyzes

A

phosphodiester bond formation

primer with free 3’ - OH –dNTP–> template strand (utilizes 1 dNTP at a time) –> replicated strand + PPi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The reaction catalyzed by DNA polymerase s

A

(DNA)n + dNTP (DNA)n+1 +PPi

22
Q

5 important characteristics of DNA synthesis

A
  1. Deoxynucleoside triphosphates and Mg2+ are required (dATP, dGTP, dCTP, dTTP)
  2. A template strand is used to direct DNA synthesis
  3. A primer from which the new strand grows must be present
  4. Utilizes ONE NUCLEOTIDE (dNTP) at a time (but very fast)
  5. many DNA polymerases have nuclease activity that allows for the removal of mismatched bases
23
Q

chain elongation is what type of reaction

A

nucleotidyl-group-transfer reaction

24
Q

nucleotides are added one at a time to the ____ end

A

3’

25
Q

chain extension is always ___ to ___ prime end

A

5’ to 3’

26
Q

what step of DNA chain elongation makes the reaction irreversible?

A

pyrophosphatase

27
Q

DNA polymerase 1 possesses 3’ to 5’ exonuclease activity aka

A

proofreading

28
Q

polymerase 1 can catalyze both chain

A

elongation and degradation

29
Q

polymerase 1 recognizes distortion in the DNA caused by incorrectly

A

paired bases

30
Q

exonuclease activity removes

A

mispaired nucleotide before continuing

31
Q

pairs of amino acids

A

C-G (triple bond)

T=A

32
Q

proofreading by the 3’ –> 5’ exonuclease

A

finds removes and repairs mistakes

33
Q

E. coli chromosome is

A

circular, double stranded DNA

34
Q

replication of ecoli begins at the

A

oriC = origin of replication

35
Q

DNA replication of ecoli proceeds

A

bidirectionally until the two replication complexes meet at the termination site (ter)

36
Q

purpose of DnaA

A

binds to the oriC region –> keys DNA polymerase

and recruits DnaB (helicase activity)

37
Q

replisome

A

protein machinery for replication (one replisome at each of 2 replication forks)

38
Q

in ecoli, new strands of DNA are synthesized at the

A

two replication forks where replisomes are located

39
Q

unwinds DNA

A

helicase

40
Q

generates RNA primer

A

primase

41
Q

single stranded binding protein (SSB)

A

binds to ssDNA and prevents re-annealing of the helix; they exist as tetramers; each tetramer binds A-T rich sites; binding is cooperative; ssDNA with SSB is inflexible

42
Q

the resulting complex of DNA and proteins is called the

A

prepriming complex

43
Q

DnaB is

A 
a helicase (molecular zipper); moves with directionality and processivity (holds on and doesn't let go) 
utilizes ATP to separate annealed DNA strands
44
Q

What can happen from a defect in the helicase

A

Werner’s syndrome –> premature aging

45
Q

Can DNA polymerase initiate new strands

A

NO unable to covalently link 2 individual nucleotides together; they ARE able to covalently link a nucleotide to a PRIMER

46
Q

RNA primer is synthesized by

A

primase

47
Q

primase enables

A

DNA synthesis to begin; synthesizes short RNA complementary to a DNA strand that then serves as a primer for DNA synthesis
DNA Template —Primase—> RNA primer w/ template —DNA polymerase—> Newly synthesized DNA strand w. template strand

48
Q

what is the site of replication called

A

replication fork

49
Q

replication fork moves in

A

1 direction, so both strands are copied simultaneously; however DNA polymerases synthesize DNA only in the
5’ –> 3’ direction

50
Q

Okazaki fragments

A

copy the lagging strand, which is lead by RNA primer

Biochemistry (6 decks)

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