DNA Replication

Question 1

AAA ATPase

Answer 1

DNAa binds to the origin of replication and disassociates the helical strands. The energy of ATP cleavage is used to produce a conformational change in DNAa, which forces the strands apart

Question 2

DNA Ligase

Answer 2

Creates phosphodiester bonds by using the energy of ATP cleavage. This seals “nicks” in the DNA strand.

Question 3

DNA Polymerase

Answer 3

These enzymes are responsible for strand elongation, require a ssDNA as a template and require RNA polymer

Question 4

Helicase

Answer 4

These enzymes cause disassociation of the two strands of the DNA double helix. Unwinding the structure using the energy released from ATP cleavage.

Question 5

Nucleases

Answer 5

Sever phosphodiester bonds of the DNA backbone. They can function as an endonuclease or exonuclease.

Question 6

Primase

Answer 6

Responsible for the synthesizing of short stretches of RNA complementary to the template DNA strand that serves as a primer for DNA polymerase.

Question 7

Topoisomerase

Answer 7

These enzymes adjust the supercoiling stress and introduce negative supercoiling. They contain both endonuclease function and ligase function. Type I topoisomerases cleave one of the strands of the double helix. Type II topoisomerases cleave both strands to perform their functions.

Question 8

DNA Polymerase I

Answer 8

Involved in DNA repair and removes RNA primer during replication.
Special 5’-3’ exonuclease activity

Question 9

DNA Polymerase II

Answer 9

DNA repair functions

Question 10

DNA Polymerase III

Answer 10

Synthesizes most of the DNA on both the leading and laggin strands during replication.

Question 11

DNA Polymerase IV

Answer 11

DNA Repair functions.

Question 12

DNA Polymerase V

Answer 12

DNA repair functions.

Question 13

DNA polymerase alpha

Answer 13

Contains primase. Initiates DNA synthesis. No proof reading ability.

Question 14

DNA Polymerase Beta

Answer 14

Repair. No proof reading function.

Question 15

DNA Polymerase gamma

Answer 15

Replicates mitochondrial DNA. Proof reading function.

Question 16

DNA polymerase delta

Answer 16

Thought to elongate Okazaki fragments of the lagging strand. Proof reading function (3’ - 5’ exonuclease activity)

Question 17

DNA Polymerase Epsilon

Answer 17

Thought to elongate the leading strand. Has 3’- 5’ exonuclease activity.