Question 1

An effective antibiotic is ___,which inhibits ______.

Accepted Answer

A) ciprofloxacin,DNA gyrase 
B) doxorubicin,Type IA topoisomerase 
C) novobiocin,ATPase 
D) camptothecin,Type II topoisomerase 
E) none of the above 
A) ciprofloxacin,DNA gyrase 
B) doxorubicin,Type IA topoisomerase 
C) novobiocin,ATPase 
D) camptothecin,Type II topoisomerase 
E) none of the above

Question 2

Which of the following is NOT a requirement of genetic material?

Accepted Answer

A) The lifetime of the material must be such that it can undergo repeated decoding. 
B) The material must be accessible for replication,transcription,and translation. 
C) The material must be capable of duplication. 
D) The material must perform a read only function to minimize damaging changes in structure. 
E) none of the above 
A) The lifetime of the material must be such that it can undergo repeated decoding. 
B) The material must be accessible for replication,transcription,and translation. 
C) The material must be capable of duplication. 
D) The material must perform a read only function to minimize damaging changes in structure. 
E) none of the above

Question 3

The DNA helix is stabilized by
(I)hydrogen bonds between phosphate groups.
(II)stacking interactions.
(III)an entropically favored interaction between hydrophobic groups.
(IV)favorable electrostatic interactions.

Accepted Answer

A) I,II,III,IV 
B) I,II,IV 
C) II,IV 
D) III,IV 
E) II,III 
A) I,II,III,IV 
B) I,II,IV 
C) II,IV 
D) III,IV 
E) II,III

Question 4

Matching
Choose the correct answer from the list.Not all the answers will be used.

-_________ topoisomerases that make double-strand breaks in DNA in a controlled fashion.

Accepted Answer

A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper 
A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper

Question 5

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Complementary DNA and RNA strands can be ______.

Accepted Answer

A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper 
A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper

Question 6

Based on the information in this chapter,which of the following sequences would likely bind a repressor if double stranded?

Accepted Answer

A) 5' TGAGCA3' 
B) 5' TGATCA3' 
C) 5' TACGTCA3' 
D) All of the above would bind the repressor with equal efficiency 
E) None of the above would bind would the repressor. 
A) 5' TGAGCA3' 
B) 5' TGATCA3' 
C) 5' TACGTCA3' 
D) All of the above would bind the repressor with equal efficiency 
E) None of the above would bind would the repressor.

Question 7

Which of the following is FALSE about RNA?

Accepted Answer

A) It may be double stranded in viral genomes. 
B) It may form double stranded stems by binding its complementary bases within the same strand. 
C) It always forms a single strand that resembles the structure of B-DNA. 
D) It is only synthesized as a single strand. 
E) It may be involved in the control of gene expression. 
A) It may be double stranded in viral genomes. 
B) It may form double stranded stems by binding its complementary bases within the same strand. 
C) It always forms a single strand that resembles the structure of B-DNA. 
D) It is only synthesized as a single strand. 
E) It may be involved in the control of gene expression.

Question 8

If a circular DNA containing no supercoils is incubated with ethidium bromide

Accepted Answer

A) the number of twists will increase,positive supercoils will develop,and the linking number will remain the same. 
B) the number of twists will decrease,positive supercoils will develop,and the linking number will remain the same. 
C) the number of twists will increase,negative supercoils will develop,and the linking number will remain the same. 
D) the number of twists will decrease,negative supercoils will develop,and the linking number will remain the same. 
E) the linking number will be altered,and both the writhing number and twist will adjust accordingly. 
A) the number of twists will increase,positive supercoils will develop,and the linking number will remain the same. 
B) the number of twists will decrease,positive supercoils will develop,and the linking number will remain the same. 
C) the number of twists will increase,negative supercoils will develop,and the linking number will remain the same. 
D) the number of twists will decrease,negative supercoils will develop,and the linking number will remain the same. 
E) the linking number will be altered,and both the writhing number and twist will adjust accordingly.

Question 9

Which of the following statements about the structure and conformation of DNA is FALSE?

Accepted Answer

A) DNA binding proteins distort DNA structure 
B) Changes in ionic strength can alter DNA structure 
C) Specific sequences can cause deviations in conformation. 
D) Changes in DNA conformation result from energy minimizations and do not relate to in vivo conditions. 
E) All of the above are true. 
A) DNA binding proteins distort DNA structure 
B) Changes in ionic strength can alter DNA structure 
C) Specific sequences can cause deviations in conformation. 
D) Changes in DNA conformation result from energy minimizations and do not relate to in vivo conditions. 
E) All of the above are true.

Question 10

Two circular DNAs are isolated,both with 1000 bp,are electrophoresed side-by-side:
#1: twist (T)= +100,writhing number (W)= −5
#2: twist (T)= +1000,writhing number (W)= +5

Accepted Answer

A) DNA #1 should migrate further. 
B) DNA #2 should migrate further. 
C) They should migrate the same distance. 
D) More information is required to determine. 
E) This cannot be determined regardless of additional information. 
A) DNA #1 should migrate further. 
B) DNA #2 should migrate further. 
C) They should migrate the same distance. 
D) More information is required to determine. 
E) This cannot be determined regardless of additional information.

Question 11

In A-DNA

Accepted Answer

A) the glycosidic bond is in the syn conformation with a C3'-endo sugar pucker. 
B) the glycosidic bond is in the syn conformation with a C2'-endo sugar pucker. 
C) the glycosidic bond is in the anti conformation with a C3'-endo sugar pucker. 
D) the glycosidic bond is in the anti conformation with a C2'-endo sugar pucker. 
E) the glycosidic bond conformation and sugar pucker is dependent on the base. 
A) the glycosidic bond is in the syn conformation with a C3'-endo sugar pucker. 
B) the glycosidic bond is in the syn conformation with a C2'-endo sugar pucker. 
C) the glycosidic bond is in the anti conformation with a C3'-endo sugar pucker. 
D) the glycosidic bond is in the anti conformation with a C2'-endo sugar pucker. 
E) the glycosidic bond conformation and sugar pucker is dependent on the base.

Question 12

Which of the following scientists is now accredited with generating the X-ray diffraction photograph that played a pivotal role in the discovery of the structure of B-DNA?

Accepted Answer

A) James Watson 
B) Francis Crick 
C) Maurice Wilkins 
D) Rosalind Franklin 
E) all of the above 
A) James Watson 
B) Francis Crick 
C) Maurice Wilkins 
D) Rosalind Franklin 
E) all of the above

Question 13

Which of the following statements about zinc fingers is FALSE?

Accepted Answer

A) Zinc fingers contain Cys and His residues. 
B) Zinc is tetrahedrally coordinated as part of a small compact protein domain. 
C) More than one finger can be found in a protein;as many as 60 have been observed. 
D) Zinc fingers are the predominant DNA-binding motif of restriction enzymes. 
E) A zinc finger recognizes specific sequences of DNA via its N-terminal helices. 
A) Zinc fingers contain Cys and His residues. 
B) Zinc is tetrahedrally coordinated as part of a small compact protein domain. 
C) More than one finger can be found in a protein;as many as 60 have been observed. 
D) Zinc fingers are the predominant DNA-binding motif of restriction enzymes. 
E) A zinc finger recognizes specific sequences of DNA via its N-terminal helices.

Question 14

E.coli topoisomerase III
(I)contains a hole capable of holding duplex DNA that is lined with negatively charged residues.
(II)binds the sugar-phosphate backbone such that base recognition is possible.
(III)functions by nucleophilic attack on the binding phosphate group.

Accepted Answer

A) I,II 
B) II,III 
C) I,III 
D) I only 
E) II only 
A) I,II 
B) II,III 
C) I,III 
D) I only 
E) II only

Question 15

Which of the following is FALSE regarding DNA binding to proteins?

Accepted Answer

A) Most eukaryotic transcription factors contain a conserved DNA-binding basic region. 
B) The basic regions typically bind in the major groove of its target DNA. 
C) Eukaryotic transcription factors either contain an HTH motif or resemble the met repressor. 
D) all of the above 
E) none of the above 
A) Most eukaryotic transcription factors contain a conserved DNA-binding basic region. 
B) The basic regions typically bind in the major groove of its target DNA. 
C) Eukaryotic transcription factors either contain an HTH motif or resemble the met repressor. 
D) all of the above 
E) none of the above

Question 16

Nucleosomes
(I)reduce the contour length of DNA 7-fold.
(II)are bound together by linker histones.
(III)come together to form a zigzag double helix.
(IV)contain a histone octamer.

Accepted Answer

A) I,II,III,IV 
B) II,III 
C) III,IV 
D) I,IV 
E) II,IV 
A) I,II,III,IV 
B) II,III 
C) III,IV 
D) I,IV 
E) II,IV

Question 17

Which atoms,or groups attached to them,face into the major groove of B- DNA?

Accepted Answer

A) purine 1 & 2;pyrimidine 2 & 3 
B) purine 2 & 3;pyrimidine 2 
C) purine 8 & 9;pyrimidine 1 & 6 
D) purine 6 & 7;pyrimidine 4 & 5 
E) purine 6 & 7;pyrimidine 2 
A) purine 1 & 2;pyrimidine 2 & 3 
B) purine 2 & 3;pyrimidine 2 
C) purine 8 & 9;pyrimidine 1 & 6 
D) purine 6 & 7;pyrimidine 4 & 5 
E) purine 6 & 7;pyrimidine 2

Question 18

Which of the following topoisomerases require(s)ATP hydrolysis for energy?
(I)type IA
(II)type IB
(III)type II

Accepted Answer

A) I only 
B) II only 
C) III only 
D) I,II 
E) I,II,III 
A) I only 
B) II only 
C) III only 
D) I,II 
E) I,II,III

Question 19

Matching
Choose the correct answer from the list.Not all the answers will be used.

-RNA catalysts are called ______.

Accepted Answer

A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper 
A)  type I 
B)  ribocatalyzers 
C)  C2´-endo 
D)  repressors 
E)  ethidium
F) type II
G) C3´-endo 
H) hybridized
I) interchanged
J) supercoiled
K) cooperative
L) non-cooperative
M) underwound
N) ribozymes
O) deuterium
P) zinc finger
Q) leucine zipper

Question 20

The sequence-specific binding of BamHI to DNA depends primarily on

Accepted Answer

A) hydrogen bonding and allows binding to less specific sequences as well. 
B) hydrogen bonding and precludes binding to any other sequence. 
C) stacking interactions and could be mimicked using an intercalation molecule. 
D) hydrogen bonding and could be mimicked using an intercalation molecule. 
E) none of the above 
A) hydrogen bonding and allows binding to less specific sequences as well. 
B) hydrogen bonding and precludes binding to any other sequence. 
C) stacking interactions and could be mimicked using an intercalation molecule. 
D) hydrogen bonding and could be mimicked using an intercalation molecule. 
E) none of the above

Exam 24: Nucleic Acid Structure

An effective antibiotic is ___,which inhibits ______.

Which of the following is NOT a requirement of genetic material?

The DNA helix is stabilized by (I)hydrogen bonds between phosphate groups. (II)stacking interactions. (III)an entropically favored interaction between hydrophobic groups. (IV)favorable electrostatic interactions.

Matching Choose the correct answer from the list.Not all the answers will be used. -_________ topoisomerases that make double-strand breaks in DNA in a controlled fashion.

Matching Choose the correct answer from the list.Not all the answers will be used. -Complementary DNA and RNA strands can be ______.

Based on the information in this chapter,which of the following sequences would likely bind a repressor if double stranded?

Which of the following is FALSE about RNA?

If a circular DNA containing no supercoils is incubated with ethidium bromide

Which of the following statements about the structure and conformation of DNA is FALSE?

Two circular DNAs are isolated,both with 1000 bp,are electrophoresed side-by-side: #1: twist (T)= +100,writhing number (W)= −5 #2: twist (T)= +1000,writhing number (W)= +5

In A-DNA

Which of the following scientists is now accredited with generating the X-ray diffraction photograph that played a pivotal role in the discovery of the structure of B-DNA?

Which of the following statements about zinc fingers is FALSE?

E.coli topoisomerase III (I)contains a hole capable of holding duplex DNA that is lined with negatively charged residues. (II)binds the sugar-phosphate backbone such that base recognition is possible. (III)functions by nucleophilic attack on the binding phosphate group.

Which of the following is FALSE regarding DNA binding to proteins?

Nucleosomes (I)reduce the contour length of DNA 7-fold. (II)are bound together by linker histones. (III)come together to form a zigzag double helix. (IV)contain a histone octamer.

Which atoms,or groups attached to them,face into the major groove of B- DNA?

Which of the following topoisomerases require(s)ATP hydrolysis for energy? (I)type IA (II)type IB (III)type II

Matching Choose the correct answer from the list.Not all the answers will be used. -RNA catalysts are called ______.

The sequence-specific binding of BamHI to DNA depends primarily on

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

An effective antibiotic is _,which inhibits ____.