Question 1

What is the DNA sequence (5' → 3')determined in this gel? Assume the samples were applied near the top of the gel.

Accepted Answer

A) AGGCTGGACGA 
B) AGGGGCTAGCA 
C) AGGCTGACGGA 
D) AGGCAGTCGGA 
A) AGGCTGGACGA 
B) AGGGGCTAGCA 
C) AGGCTGACGGA 
D) AGGCAGTCGGA

Question 2

The correct assembly of proteins needed for DNA replication at the correct site on DNA is the ________ stage.

Accepted Answer

A) termination 
B) disassembly 
C) elongation 
D) initiation 
A) termination 
B) disassembly 
C) elongation 
D) initiation

Question 3

Which subunit of the replisome leads at the replication fork?

Accepted Answer

A) β-clamp. 
B) SSB. 
C) Primosome. 
D) Polymerase core complex. 
A) β-clamp. 
B) SSB. 
C) Primosome. 
D) Polymerase core complex.

Question 4

Since deamination is a common cause of DNA damage,and since the deamination of cytosine forms a product similar in structure to uracil,repair enzymes cannot repair this damage easily.

Accepted Answer

A) True 
 B)False

Question 5

The RNA primer at the beginning of each Okazaki fragment is removed by

Accepted Answer

A) DNA polymerase I. 
B) DNA polymerase II. 
C) DNA polymerase III. 
D) 3' → 5' exonuclease subunit of DNA polymerase III. 
A) DNA polymerase I. 
B) DNA polymerase II. 
C) DNA polymerase III. 
D) 3' → 5' exonuclease subunit of DNA polymerase III.

Question 6

All DNA ligase enzymes use ATP as a cosubstrate.

Accepted Answer

A) True 
 B)False

Question 7

Nick translation is a process for

Accepted Answer

A) filling in and sealing the gap in DNA after removal of the RNA primer. 
B) synthesis of the protein for primase from mRNA. 
C) removal of the RNA primer by DNA polymerase I. 
D) removal of Okazaki fragments. 
A) filling in and sealing the gap in DNA after removal of the RNA primer. 
B) synthesis of the protein for primase from mRNA. 
C) removal of the RNA primer by DNA polymerase I. 
D) removal of Okazaki fragments.

Question 8

The Klenow fragment can be used for DNA sequencing if proteins such as SSB protein are added.

Accepted Answer

A) True 
 B)False

Question 9

In E.coli replication begins at the origin of replication and proceeds in one direction until the entire circular DNA molecule has been copied.

Accepted Answer

A) True 
 B)False

Question 10

At one point during DNA recombination in E.coli there is formation of a triple-stranded DNA.

Accepted Answer

A) True 
 B)False

Question 11

The β subunits of E.coli DNA polymerase form a sliding clamp that surrounds the DNA strands at the replication fork.

Accepted Answer

A) True 
 B)False

Question 12

The epsilon subunit of DNA polymerase III is responsible for its ________ activity.

Accepted Answer

A) 5' → 3' polymerase 
B) sliding clamp 
C) 3' → 5' exonuclease (proof reading) 
D) ribosome assembly 
A) 5' → 3' polymerase 
B) sliding clamp 
C) 3' → 5' exonuclease (proof reading) 
D) ribosome assembly

Question 13

The polymerization of DNA is essentially irreversible due to the hydrolysis of pyrophosphate.

Accepted Answer

A) True 
 B)False

Question 14

E.coli DNA polymerase catalyzes polymerization in the ________ direction(s).

Accepted Answer

A) 5' → 3' 
B) 3' → 5' 
C) 2' → 5' 
D) both 5' → 3' and 3' → 5' 
E) All of the above 
A) 5' → 3' 
B) 3' → 5' 
C) 2' → 5' 
D) both 5' → 3' and 3' → 5' 
E) All of the above

Question 15

DNA polymerase III is the largest DNA polymerase in E.coli.

Accepted Answer

A) True 
 B)False

Question 16

DNA polymerase I which is inhibited by dideoxynucleoside triphosphates is used in the Sanger method for DNA sequencing.

Accepted Answer

A) True 
 B)False

Question 17

Okazaki fragments are ________.

Accepted Answer

A) the smallest subunits of DNA polymerase III 
B) short stretches of DNA formed on the lagging strand 
C) short RNA primers needed for initiation of polymerization 
D) fragments of DNA polymerase I that lack 5' → 3' exonuclease activity 
A) the smallest subunits of DNA polymerase III 
B) short stretches of DNA formed on the lagging strand 
C) short RNA primers needed for initiation of polymerization 
D) fragments of DNA polymerase I that lack 5' → 3' exonuclease activity

Question 18

At the normal rate of replication,about how many minutes does it take for the entire E.coli chromosome (4.6 × 103 kbp)to be duplicated?

Accepted Answer

A) 5 
B) 20 
C) 40 
D) 80 
A) 5 
B) 20 
C) 40 
D) 80

Question 19

Approximately ________ base pairs are added per second during DNA in vivo replication in E.coli.

Accepted Answer

A) 10 
B) 100 
C) 1000 
D) 1,000,000 
A) 10 
B) 100 
C) 1000 
D) 1,000,000

Question 20

In E.coli the helicase ________ is one of the subunits of the ________ in the replisome.

Accepted Answer

A) gyrase;primosome 
B) gyrase;β-clamp 
C) DnaB;primosome 
D) DnaB;β-clamp 
A) gyrase;primosome 
B) gyrase;β-clamp 
C) DnaB;primosome 
D) DnaB;β-clamp

Exam 20: DNA Replication, repair, and Recombination

What is the DNA sequence (5' → 3')determined in this gel? Assume the samples were applied near the top of the gel.

The correct assembly of proteins needed for DNA replication at the correct site on DNA is the ________ stage.

Which subunit of the replisome leads at the replication fork?

Since deamination is a common cause of DNA damage,and since the deamination of cytosine forms a product similar in structure to uracil,repair enzymes cannot repair this damage easily.

The RNA primer at the beginning of each Okazaki fragment is removed by

All DNA ligase enzymes use ATP as a cosubstrate.

Nick translation is a process for

The Klenow fragment can be used for DNA sequencing if proteins such as SSB protein are added.

In E.coli replication begins at the origin of replication and proceeds in one direction until the entire circular DNA molecule has been copied.

At one point during DNA recombination in E.coli there is formation of a triple-stranded DNA.

The β subunits of E.coli DNA polymerase form a sliding clamp that surrounds the DNA strands at the replication fork.

The epsilon subunit of DNA polymerase III is responsible for its ________ activity.

The polymerization of DNA is essentially irreversible due to the hydrolysis of pyrophosphate.

E.coli DNA polymerase catalyzes polymerization in the ________ direction(s).

DNA polymerase III is the largest DNA polymerase in E.coli.

DNA polymerase I which is inhibited by dideoxynucleoside triphosphates is used in the Sanger method for DNA sequencing.

Okazaki fragments are ________.

At the normal rate of replication,about how many minutes does it take for the entire E.coli chromosome (4.6 × 103 kbp)to be duplicated?

Approximately ________ base pairs are added per second during DNA in vivo replication in E.coli.

In E.coli the helicase ________ is one of the subunits of the ________ in the replisome.

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Transcription and RNA Processing

Protein Synthesis

Filters

In E.coli the helicase is one of the subunits of the in the replisome.