DNA Replication (P1)

Question 1

Each daughter DNA has one strand from the ____________ and one
_____ strand

Answer 1

template, new

Question 2

Initiator proteins call ______ in prokaryotes bind at the _________________________
causing the adjacent opening

Answer 2

DnaA, origin of replication sequence

Question 3

What are the three key enzymes involved in unwinding and what purpose do they serve - Helicase

Answer 3

Unwinds DNA strands

Question 4

What are the three key enzymes involved in unwinding and what purpose do they serve - DNA Gyrase

Answer 4

A type of topoisomerase that works ahead of the
replication fork to reduce positive supercoiling

Question 5

What are the three key enzymes involved in unwinding and what purpose do they serve - Single stranded binding proteins

Answer 5

Prevent strands from binding
back together

Question 6

What direction does polymerization occur?

Answer 6

5’ to 3’ direction on the newly synthesized strand

Question 7

True or False: RNA polymerases require a 3’OH group to begin polymerization.

Answer 7

False

Question 8

How do DNA polymerases determine when 3’->5’ exonuclease activity is necessary?

Answer 8

By detecting abnormal widths in the DNA indicative of the wrong nucleotide added

Question 9

True or False: DNA polymerase III can only move in the 5’ to 3’ direction

Answer 9

False

Question 10

True or False: DNA synthesis uses only one primer per strand for polymerization.

Answer 10

False

Question 11

In what directions are the leading and lagging strands synthesized?

Answer 11

Leading: Towards the replication fork
Lagging: Away from the replication fork

Question 12

What is one way termination does NOT occur in prokaryotes?

Answer 12

The end of the chromosome is reached

Question 13

What is one issue that arises in termination for eukaryotes? What enzyme fixes this problem?

Answer 13

Gradual shortening of the chromosome due to the incomplete DNA synthesis on the lagging strand. Telomerase is used to extend the end of the chromosome by adding additional repeat sequences.

Question 14

What serves as a template for telomere DNA synthesis?

Answer 14

RNA template on telomerase that is complementary to the 3’
overhang on the leading strand

Question 15

On which end of the DNA strand do telomeres shorten?

Answer 15

5’ end of the lagging strand

Question 16

What type of DNA is found at the ends of chromosomes?

Answer 16

Tandem repeats