Brainscape's Knowledge GenomeTM

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


See full index

Y2S2 - Adv. Molecular Biology > MolBio5 - 36 > Flashcards

MolBio5 - 36 Flashcards

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

What breaks down Ppi into 2Pi?

A

Pyrophosphatase

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

Why is DNA synthesis said to be irreversible?

A

It involves the breakdown of Ppi into 2Pi

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

What provides the energy for DNA synthesis?

A

Breakage of two high energy phosphate bonds

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

What is the energy usage of DNA replication?

A

-7kCal/mol

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

Describe the direction of DNA synthesis?

A

Bidirectional

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

What removes the RNA primers of the okazaki fragments?

A

Ribonuclease H

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

What makes the okazaki fragments continuous?

A

DNA ligase

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

What are the 9 replication proteins?

A

Helicase, single-stranded binding proteins, primase, polymerase, sliding clamp, clamp loader, ribonuclease H, ligase and topoisomerase

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

What does ribonuclease H do?

A

Removes RNA primers

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

What does DNA ligase do?

A

Uses the energy of ATP hydrolysis to ligate newly synthesise, adjacent DNA fragments in a two-step catalytic reaction

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

Outline the first step of DNA ligase

A

ATP + 5’-P > P-P + 5’-P-AMP

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

Outline the second step of DNA ligase

A

P-P > 2Pi + free energy

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

What is the ligation process described as?

A

Energetically highly favourable

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

What keeps the ligation process energetically highly favourable?

A

Phyrophosphatase

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

What does DNA primase do?

A

Synthesis a short RNA primer required by ALL DNA for synthesis initiation

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

What does DNA helicase do?

A

Uses ATP to separate the parental DNA strands at the replication fork and moves the fork forwards

17
Q

What is DNA helicase activity reliant upon?

A

ATP and magnesium

18
Q

What can mutations in helicase activity cause?

A

Progeria, such as Werner Syndrome, resulting in premature aging

19
Q

Describe Werner Syndrome

A

A form of progeria, mutation are AR in RECQ helicase gene WRN

20
Q

What aids DNA polymerase?

A

Sliding clamp and clamp loader

21
Q

How do sliding clamp and clamp loader help DNA polymerase?

A

Sliding clamp is positioned close to the primer:template junction by clamp loader, encircling the DNA like a nut on a bolt to help move the DNA polymerase forwards

22
Q

What do single-stranded binding proteins do?

A

Expose single-stranded DNA in the replication fork, making it available for templating synthesis of the new DNA strand and easing replication fork progression

23
Q

What do DNA topoisomerases do?

A

Prevent DNA from becoming tangled during DNA replication

24
Q

How do DNA topoisomerase prevent DNA from becoming tangled?

A

Nick and reseal the backbone of the parental helix to relieve superhelical tension

25
Q

What do type I topoisomerases do?

A

Nick and reseal one of the 2 DNA strands, ATP independently

26
Q

What do type II topoisomerases do?

A

Nick and reseal both of the DNA strands, ATP dependently

27
Q

Describe replication initiation

A

Biphasic - replicator selection occurs in G1, then origin activation occurs in S phase

28
Q

Outline origin activation

A

Unwinding of DNA and recruitment of DNA polymerase

29
Q

What is temporal seperation in terms of replication control?

A

Ensures replicator selection and origin activation are seperated by a fixed amount of time, ensuring each chromosome is only replicated exactly once per cell cycle

30
Q

Outline the mechanism of pre-replicative complex construction

A

Origin recognition complex (ORC) binds to replicator sequence, helicase loading proteins Cdc6 and Cdt1 binds to ORC, helicase Mcm2-7 binds to complete formation of pre-RC

31
Q

How is the pre-replicative copmlex is controlled?

A

Low Cdk = pre-RC formation allowed, no activation; high Cdk = no pre-RC formation allowed, pre-RC activation

32
Q

What is the end replication problem?

A

Need for an RNA primer for initiation of DNA synthesis needs to be removed, but eventually this would lead to chromosome shortening

33
Q

What is added to DNA after replication, and why?

A

TTAGGG repeats by telomerase to compensate for the loss of telomere sequences caused by RNA primer removal

Y2S2 - Adv. Molecular Biology (14 decks)

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