DNA replication (M1B1) Flashcards

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

what is DNA replication?

A

it is the synthesis of new DNA molecule

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

when does DNA synthesis occur?

A

S phase

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

what is semiconservative?

A

following replication, each daughter molecule of DNA contains 1 intact parental strand and 1 newly synthesized strand joined by base pairs

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

what does bidirectional mean?

A

that replication begins at a site of origin and simultaneously moves out in both directions from that point

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

DNA replication is both semiconservative and bidirectional

A

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

prokaryotes have 1 origin of replication called?

A

oric

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

eukaryotes have multiple replication origins

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • how many hydrogen bonds are holding AT together?

- how many hydrogen bonds are holding GC together?

A
  • 2

- 3

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

AT are easier to separate than GC cuz?

A

their melting point is less

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

what are the 5 steps of replication?

A

1) unwinding
2) formation of RNA primer
3) synthesis of new DNA strands
4) excision of RNA primer and their replacement with DNA
5) proof reading n editing

UFSEP

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

where does unwinding occur and what does it create?

A

origin of replication, 2 replication forks (group of proteins responsible for separation of DNA strands)

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

an enzyme that separates the 2 strands of DNA by cleaving (splitting) the hydrogen bonds is called?

A

DNA Helicase

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

proteins that hold the separated strands how from each other created by helicase so they don’t foil again are called?

A

single-strand binding proteins (SSBP)

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

the local unwinding in one region leads to super coiling in front of the separated part which prevents?

A

further separation of the helix

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

enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule?

A

DNA polymerase

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

what release the super coils by transient cutting of the phosphodiester bonds in 1 or 2 strands of DNA?

A

tropoisomerases

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

what are the types of tropoisomerases and the function?

A
  • tropoisomerases 1: it can make transient cut in 1 DNA strand. doesn’t require energy
  • tropoisomerases 2: it can make transient citizens both DNA strands. requires ATP for energy.
18
Q

clinically chemicals that inhibit tropoisomerases in humans are in? while the ones that inhibit prokaryotes are used as?

A
  • chemotherapy ex. etoposide

- antibiotic ex. quinolone

19
Q

the enzyme that synthesizes DNA cannot initiate replication it needs a……….?

A

primer

20
Q

enzyme that creates the primer is called?

A

primase

21
Q

RNA primer is a short fragment of RNA (about 10 nucleotides)

A

22
Q

RNA primer needs what enzyme for its synthesis in 5’-3’ direction?

A

primase enzyme

23
Q

RNA primer is removed later on for the other DNA strand to bind

A

24
Q

DNA polymerase are also called?

A

DNA dependent DNA polymerase

25
Q

why is DNA dependent DNA polymerase called that?

A

cuz it DNA polymerase synthesis new dna strand depending on the templet which is DNA

26
Q

how many types are there of DNA polymerase

A

5

(they are a group of enzymes responsible for adding complementary deoxynucleotides to 3’OH and of pre-existing nucleotide)

26
Q

dna polymerase can only synthesis in 1 direction which is?

A

5’ to 3’ direction

28
Q

when the new strand joins the old strand a phosphodiester bond forms between adjacent nucleotides (AT GC)

A

29
Q

each precursor pairs with the complete add on the template strand and forms a phosphodiester bond with 3’hydroxyl end of the growing chain with the release of?

A

pyrophosphate

30
Q

DNA polymerase catalyze the synthesis of DNA, they are called?

A

DNA dependent DNA polymerase

31
Q

how many eukaryote types of DNA polymerase are there?

A

5

32
Q

what is DNA-dependent DNA polymerases responsible for?

A

adding complementary deoxynucleotides to 3’OH end of preexisting nucleotide and RNA primer (cannot initiate DNA synthesis)

34
Q
  • leading strand moves in what direction?

- lagging strand moves in what direction?

A
  • 3’-5’ direction (same as the replication fork)

- 5’-3’ (opp. the replication fork)

35
Q

in the leading strand there is only need of 1 RNA primer to synthesis following the replication fork aka CONTINUOUS while in the lagging strand needs another RNA primers to synthesis moving the opposite direction aka DISCONTINUOUS

A

36
Q

The leading strand extended from one primer alone, the lagging strand needs a new primer for each of the short okazaki fragments

A

37
Q

okazaki fragments are only present on?

A

lagging strands (each piece had its RNA primer

38
Q

when the rna primer is done what excises it off?

A

RNase H

39
Q

gaps resulted from excised RNA primer are filled by?

A

deoxyribonucleotides (with help of DNA polymerase)

40
Q

An enzyme that catalyses formation of Phosphodiester Bonds between two polynucleotide chains And joins DNA fragments together is called?

A

DNA ligase (needs ATP)

41
Q

many of the antiviral drugs used in the treatment of HIV are analogs of?

A

deoxyribonucleoside triphosphates

ex. the drug zidovudine that contains thymidine that lacks 3’-hydroxyl. which interferes in the growth and multiplication of virus causing its death