DNA Replication

Question 1

What is the function of the exonuclease domain in DNA polymerase?

Answer 1

To detect mismatch of bases.

Question 2

What are the 3 stages of DNA replication?

Answer 2

Initiation
Elongation
Termination

Question 3

Describe initiation in DNA replication…

Answer 3

The enzyme Primase allows the recruitment of DNA polymerase.

Polymerase attaches to the 3’ in order to elongate in the 5’ to 3’ direction.

Question 4

Describe elongation in DNA replication…

Answer 4

DNA polymerase forms phosphodiester bonds
Leading strand and lagging strand (lagging has Okazaki fragments, joined by Ligase

There can be a fork at both ends of the strand

Helicase unzips the strand

Question 5

What is the general equation for the formation of a phosphodiester bond?

Answer 5

(dNMP)n + dNTP —>(dNMP)n+1 + PPi

Bond formation driven by pyrophosphate hydrolysis.

Question 6

Where does DNA replication begin on a chromosome?

Answer 6

At origins of replication.