Unit 8.2

Question 1

What does Helicase do?

Answer 1

breaks hydrogen bonds and separates the two strands in the DNA

Question 2

What does Primase do?

Answer 2

adds RNA primers

Question 3

What does DNA Polymerase III do?

Answer 3

adds new nucleotides onto RNA primers

Question 4

What does DNA Polymerase I do?

Answer 4

replaces RNA primers with nucleotides

Question 5

What does Ligase do?

Answer 5

joins okazaki fragments

Question 6

What’s the difference between the leading strand and the lagging strand?

Answer 6

the lagging strand replicates discontinuously forming short fragments, whereas the leading strand replicates continuously

Question 7

What are Okazaki fragments?

Answer 7

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 8

Describe how conservative DNA replication works?

Answer 8

the strands of the original DNA are copied but the DNA molecule remains intact

Question 9

Describe how semi-conservative DNA replication works?

Answer 9

the strands are copied then pair with the new strands

Question 10

Describe how dispersive DNA replication works?

Answer 10

the strands are cut into parts then copied, rearranged, and rebuilt into ‘dispersed’ molecules

Question 11

What does 3’ attach to? What does 5’ attach to?

Answer 11

3’ attaches to hydroxyl
5’ attaches to phosphate