Question

Match the enzyme activity in DNA synthesis with its function. DNA pol III (_) fragments Helicase (_) Primase (_) using template strand DNA pol I (_) double helix DNA ligase (_) adds nucleotides Topoisomerase (_) primer A. anneals DNA B. relieves overwinding C. adds nucleotides D. unwinds parental E. removes RNA primer, F. adds a short RNA 10 Proofreading and repair of the DNA double helix does NOT involves a. detecting a mis-match in base pairs. b. removing the mis-match with a nuclease. c. annealing the Okazaki fragments together with DNA ligase. d. repairing the mis-match with polymerase. e. annealing the edited DNA with the rest of the molecule with ligase.

Answer 1

4. DNA Pol III- (C)- DNA polymerase III is the primary enzyme involved in DNA replication which adds nucleotides to the 3' end of the forming DNA strand during replication.

5. Helicase- (D)- Helicases are enzymes that separates double-stranded DNA into single strands allowing each strand to be copied.

6. Primase- (F)- Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded DNA.

7. DNA Pol I- (E)- DNA polymerase-I fills in the necessary nucleotides between the Okazaki fragments in a 5'→3' direction.

8. DNA ligase- (A)- DNA ligases are essential for the joining of DNA fragments during replication.

9. Topoisomerase- (B)-Topoisomerases are enzymes that participate in the overwinding or underwinding of DNA.

10. Okazaki fragments are only formed during DNA replication and not observed during DNA proof reading and repair. Therefore answer is (C)