L5 DNA Replication Flashcards Preview

BMS242 Cell & Molecular > L5 DNA Replication > Flashcards

Flashcards in L5 DNA Replication Deck (33)
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1

DNA replication is

semi-conservative

2

DNA synthesis direction

5' to 3' direction

3

DNA strand orientiation

anti-parallel

4

DNA synthesis initiation

replication fork

5

DNA helicase function

separate paired strands of DNA

6

Okazaki fragments

occurs on lagging strand

7

Which strand is continuous

leading strand

8

Requirements for DNA chain synthesis

DNA polymerase

9

What do DNA polymerases require for DNA synthesis

pre-existing chain or primer

10

Primer

short stretch of nucleotides

11

Action of DNA polymerase on the RNA primer

extends the primer

12

What does lagging strand synthesis require

DNA primase, DNA polymerase, Ribonuclease H and DNA ligase

13

Ribonuclease H function

removes RNA primer

14

True or False - DNA helicase requires ATP

true

15

Diseases caused by mutations in DNA helicase

Werner Syndrome, Bloom syndrome

16

Werner syndrome

premature ageing

17

Bloom syndrome

rare cancer syndrome

18

Sliding clamp function

enhances DNA polymerase processivity, move DNA polymerase forward

19

Single stranded DNA binding protein function

expose single stranded DNA in the replication fork, enhance processivity of DNA polymerase

20

DNA topoisomerases function

prevent DNA becoming tangled during replication

21

Which DNA topoisomerase requires ATP

topoisomerase II

22

Origin of replication

where DNA replication begins

23

Yeast origins

autonomously replicating sequences

24

Human origins

poorly understood, sequences near to LMNB2, MYC

25

What are human origins also defined by

chromatin structure

26

When does replicator selection occyr

G1

27

When does origin activation occur

S phase

28

What does eukaryotic replicator selection form

pre-replicative complex

29

Origin replication complex function

bind to replicator sequence

30

Relationship between pre-RC and Cdk function

ensures chromosomes are replicated exactly once per cell cycle