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
31
What is the effect of removing RNA primers
shortens newly synthesised DNA strands
32
What is telomerase
protein and RNA
33
