SG 2.4

Question 1

Definition of helicase

Answer 1

Breaks the strands of the double helix

Question 2

Definition of primase

Answer 2

Adds RNA nucleotides (primers) to the broken double helix.

Question 3

Definition of DNA polymerase III

Answer 3

Adds DNA nucleotides to both of the original strands.

Question 4

Definition of DNA polymerase I

Answer 4

Removes RNA primer and replaces RNA nulceotides with DNA nucleotides.

Question 5

Definition of ligase

Answer 5

Goes back and binds sugars and phosphates.

Question 6

Definition of lagging strand

Answer 6

One of two strands of DNA found at the replication fork, or junction, in the double helix.

Question 7

Definition of leading strand

Answer 7

The strand of nascent DNA which is synthesized in the same direction as the growing replication fork.

Question 8

What is an Okazaki fragment?

Answer 8

Short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication.

Question 9

Definition of anti-parallel structure

Answer 9

The strands run in opposite directions, parallel to one another.

Question 10

What functional group is attached to the 3’ carbon? What functional group is attached to the 5’ carbon?

Answer 10

3’ = hydroxyl
5’ = phosphate