Brainscape's Knowledge GenomeTM

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


See full index

► Genetics > Exam 2: DNA & Replication > Flashcards

Exam 2: DNA & Replication Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

3 parts of a nucleotide

A

sugar

phosphate

nitrogenous base

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

complementary base pairs

A

A—T with 2 bonds

G—C with 3 bonds

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

what is needed to make dsDNA

A

antiparallel strands with complementary base pairs

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

what stabilizes dsDNA

A

Mg2+ ions

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

Watson-Crick Model

A 
2 antiparallel strands
right-handed double helix
phosphate backbones on the outside
h-bonding from the bases on the inside
complementary pairs
Mg2+ ions to stabilize helix backbone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

in vitro

A

in glass (test tube)

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

in vivo

A

in life

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

DNA replication in vitro is a ____

A

cell free system

you only use chemicals

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

5 things needed for in vitro DNA replication

A

DNA nucleotides in triphosphate form

a ssDNA template strand

a DNA primer

DNA polymerase enzyme

Mg2+ ions

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

what happens in in vitro DNA replication

A

DNA polymerase binds at the 3’ end of the primer

DNA polymerase extends the primer from 3’ to 5’

5’—3’(primer)-DNA polymerase—»
3’———–template——————–5’

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

what yields E for synthesis?

A

2 phosphates from the triphosphate nucleotides are lost in synthesis

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

Mg 2+

A

2 ions involved in each nucleotide addition (stabilization)

a cofactor of DNA polymerase

neutralizes charge repulsion of oxygens in DNA backbone

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

complications of in vivo DNA replication in E. coli

A

2 strands are wrapped around eachother and have to separate and replicate in opposite directions

unwinding can cause supercoiling

there is no primer when the two strands open up and separate

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

how many forks does in vivo DNA replication have?

A

two forks going in opposite directions at the same time

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

is there a primer in natural DNA replication?

A

no, there is a temporary short primer made of RNA

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

primase

A

an enzyme that makes short temporary primers from RNA

17
Q

semidiscontinuous replication

A

differences in the way synthesis occours on the leading and lagging strand

18
Q

the leading strand

A

is replicated continuously towards the fork

19
Q

the lagging strand

A

is replicated discontinuously away from the fork

20
Q

supercoil

A

when DNA unravels the strand uncoils and supercoils into loops

21
Q

supercoils on short pieces of dsDNA

A

don’t last long, they spin out

22
Q

supercoils on long linear DNA or circular DNA

A

accumulate

23
Q

should supercoils be removed?

A

yes they must in both replication and transcription

24
Q

how are supercoils removed?

A

with the enzyme topoisomerase

25
Q

topoisomerase

A

2 types (1 & 2)

enzymes that cut dsDNA either in one strand or 2 strands

26
Q

topoisomerase 1

A

cuts dsDNA on 1 strand

1) nick
2) rotate
3) ligate

27
Q

topoisomerase 2

A

cuts dsDNA on 2 strands

1) double-strand break
2) pass through
3) rejoin

28
Q

okazaki fragments

A

created during discontinuous synthesis on the lagging strand

contains an RNA primer on 5’ end and attached strand of ssDNA to 3’ end

5’-RRRRDDDD,RRRRDDDD-3’

29
Q

DNA polymerase 1

A

connects Okazaki fragments by removing RNA nucleotides one by one from right of nick

attaches DNA nucleotides to left of the nick

RRRRDDDD
D,RRRDDDD
DD,RRDDDD

30
Q

3 major differences in DNA replication in eukaryokes

A

chromosomes

packaging of DNA

rate of replication

31
Q

chromosomes in eukaryote DNA replication

A

long, linear, end in telomeres

telomerase enzyme needed to restore chromosome ends

32
Q

in eukaryotes, replication starts at…

A

replicon origins/bubbles that extend and meet each other

early and late replicating areas are organized locally into replicon families

33
Q

DNA packaging in eukaryotes

A

chromatin has nucleosome (spooled) structure

histone proteins for nucleosomes are synthesized

nucleosome cores are replicated dispersively-old and new are divided randomly into new strands

34
Q

eukaryoke DNA replication rate

A

movement of forks is slower

rate is 2000-10000 bp/min

~ 10,000 origins in mammalian genome

300,000 bp/replicon

35
Q

what end does the primer go on?

A

3’

36
Q

semiconservative replication

A

in every dsDNA one strand is the parent of the other

37
Q

ori

A

single origin of replication in circular chromosome of a bacterium like E. coli

38
Q

where on E. coli does replication begin and end

A

begins at ori and ends on other side of circular chromosome where the forks meet

► Genetics (33 decks)

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