Section 2: DNA Polymerases and Enzymes

Part 2

DNA polymerase I was first isolated by:
A) Watson
B) Taylor
C) Meselson
D) Kornberg

D

DNA polymerase I requires which of the following to synthesize DNA?
A) RNA template
B) Ribosomes
C) DNA template and dNTPs
D) rNTPs only

C

The polA1 mutant of E. coli showed that DNA polymerase I:
A) Functions mainly in DNA repair
B) Is essential for replication
C) Is responsible for helicase activity
D) Synthesizes RNA primers

A

Chain elongation by DNA polymerase occurs in which direction?
A) Random
B) Bidirectional
C) 3’ → 5’
D) 5’ → 3’

D

Which enzyme removes RNA primers in E. coli?
A) DNA polymerase III
B) DNA polymerase I
C) DNA ligase
D) Primase

B

Which polymerase is responsible for the bulk of DNA synthesis in E. coli?
A) Pol I
B) Pol II
C) Pol III
D) Pol IV

C

Which polymerase has 5’ → 3’ exonuclease activity?
A) Pol I
B) Pol II
C) Pol III
D) Pol V

A

Which subunit of Pol III is responsible for 5’ → 3’ polymerization?
A) α (alpha)
B) ε (epsilon)
C) θ (theta)
D) τ (tau)

A

The ε subunit of Pol III provides:
A) Catalytic polymerization activity
B) Proofreading (3’ → 5’ exonuclease) activity
C) Helicase activity
D) Primer synthesis

B

The β sliding clamp in Pol III functions to:
A) Initiate RNA primer synthesis
B) Increase processivity of DNA synthesis
C) Excise mismatched bases
D) Load helicase onto DNA

B