DNA replication

Question 1

Helicase

Answer 1

Unwinds DNA template at replication fork

Question 2

Single stranded binding proteins

Answer 2

Stabilize unwound DNA; prevent strands from reannealing

Question 3

DNA topoisomerases

Answer 3

Create a single or double stranded break in the helix downstream to add or remove supercoils

Question 4

DNA gyrase

Answer 4

Prokaryotic topoisomerase II

Inhibited by Fluoroquinolones

Question 5

Primase

Answer 5

Makes an RNA primer on which DNA Polymerase III can initiate replication

Question 6

DNA polymerase III

Answer 6

Prokaryotic only
Builds leading and lagging strands
Has 5’->3’ synthesis
Proofreads with 3’->5’ exonuclease

Question 7

DNA Polymerase I

Answer 7

Prokaryotic only
Degrades RNA primer and replaces it with DNA
Acts like DNA Pol III as exonuclease, but is 5’-> 3’ exonuclease

Question 8

DNA ligase

Answer 8

Catalyzes formation of a phosphodiester bond within a strand of dsDNA (seals Okazaki fragments)

Question 9

Telomerase

Answer 9

RNA-dependent DNA polymerase that adds DNA to 3’ ends of chromosomes to avoid loss of genetic material w/each duplication.

Question 10

DNA polymerase alpha

Answer 10

In eukaryotes only - makes its own primer to build Okazaki fragments on the lagging strand

Question 11

DNA polymerase delta

Answer 11

Builds DNA leading strand in eukaryotes

Question 12

How does UV light damage DNA?

Answer 12

Creates pyrimidine dimers on same strand of DNA

Question 13

What replicates the lagging strand in eukaryotes

Answer 13

DNA polymerase alpha

Question 14

What synthesizes RNA primer in eukaryotes

Answer 14

DNA polymerase alpha

Question 15

What repairs DNA in eukaryotes

Answer 15

DNA polymerase beta

Question 16

What replicates mitochondrial DNA in eukaryotes

Answer 16

DNA polymerase gamma

Question 17

What replicates leading strand DNA in eukaryotes

Answer 17

DNA polymerase delta