Question 1

Orotate is synthesized from

Accepted Answer

A) glycine and carbamoyl phosphate. 
B) arginine and carbamoyl phosphate. 
C) aspartate and carbamoyl phosphate. 
D) aspartate and glutamine. 
E) asparagine and glutamine. 
A) glycine and carbamoyl phosphate. 
B) arginine and carbamoyl phosphate. 
C) aspartate and carbamoyl phosphate. 
D) aspartate and glutamine. 
E) asparagine and glutamine. C

Question 2

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

-The electrons used to convert an NDP to a dNDP ultimately come from ______.

Accepted Answer

A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate 
A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate B

Question 3

In animals,elevated levels of PRPP will

Accepted Answer

A) activate pyrimidine biosynthesis. 
B) activate purine biosynthesis. 
C) activate both pyrimidine and purine biosynthesis. 
D) inhibit pyrimidine biosynthesis;activate purine biosynthesis. 
E) inhibit purine biosynthesis;activate pyrimidine biosynthesis. 
A) activate pyrimidine biosynthesis. 
B) activate purine biosynthesis. 
C) activate both pyrimidine and purine biosynthesis. 
D) inhibit pyrimidine biosynthesis;activate purine biosynthesis. 
E) inhibit purine biosynthesis;activate pyrimidine biosynthesis. C

Question 4

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

-The precursor to AMP and GMP is ______.

Accepted Answer

A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate 
A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate

Question 5

The symptoms of Lesch-Nyhan syndrome are caused by a deficiency of which of the following enzymes?

Accepted Answer

A) adenine phosphoribosyltransferase 
B) HGPRT (hypoxanthine-guanine phosphoribosyltransferase) 
C) adenosine deaminase 
D) dihydrofolate reductase 
E) xanthine oxidase 
A) adenine phosphoribosyltransferase 
B) HGPRT (hypoxanthine-guanine phosphoribosyltransferase) 
C) adenosine deaminase 
D) dihydrofolate reductase 
E) xanthine oxidase

Question 6

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

-During the turnover of nucleic acids some purines can be reincorporated into nucleotides via _____ pathways.

Accepted Answer

A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate 
A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate

Question 7

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

-In purine synthesis the byproduct released when aspartate functions as an amino group donor is ________.

Accepted Answer

A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate 
A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate

Question 8

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

-Mechanism-based inhibitors are also called _____ substrates.

Accepted Answer

A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate 
A)  fumarate 
B)  NADPH 
C)  salvage 
D)  uric acid 
E)  oxidation
F) XMP
G) iron
H) allopurinol
I) IMP
J) Oxidation
K) therapeutic
L) suicide
M) molybdenum
N) FADH
O) Malonyl-CoA
P) reduction
Q) antifolate

Question 9

The anticancer drug methotrexate inhibits nucleotide synthesis.Which of the following explains why it also inhibits the synthesis of histidine and methionine?

Accepted Answer

A) The synthetic pathways for these amino acids require tetrahydrofolate for group transfer reactions. 
B) These amino acids are derivatives of the nucleotides UTP and GTP. 
C) Without the synthesis of nucleotides,there is not sufficient energy for the synthesis of the amino acids. 
D) <ethotrexate inhibits also inhibits the precursors for these amino acids. 
E) all of the above 
A) The synthetic pathways for these amino acids require tetrahydrofolate for group transfer reactions. 
B) These amino acids are derivatives of the nucleotides UTP and GTP. 
C) Without the synthesis of nucleotides,there is not sufficient energy for the synthesis of the amino acids. 
D) <ethotrexate inhibits also inhibits the precursors for these amino acids. 
E) all of the above

Question 10

The thymidylate synthase reaction is unique because

Accepted Answer

A) THF is regenerated by the same enzyme. 
B) THF is regenerated via a two-step reaction. 
C) THF is oxidized to DHF;no other reaction alters the THF oxidation state. 
D) None of the above is correct. 
E) All of the above are correct. 
A) THF is regenerated by the same enzyme. 
B) THF is regenerated via a two-step reaction. 
C) THF is oxidized to DHF;no other reaction alters the THF oxidation state. 
D) None of the above is correct. 
E) All of the above are correct.

Question 11

The conversion of dUMP to dTMP by thymidylate synthase requires which of the following cofactors?
(I)thioredoxin
(II)N5,N10-methylenetetrahydrofolate
(III)S-adenosylmethionine

Accepted Answer

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

Question 12

Rank the additions to the rings in order of formation.

Accepted Answer

A) C,B,A,F,D,E 
B) C,E,D,C,F,A,B 
C) A,C ,D ,E ,F ,B 
D) D,F,A,C,B,E 
E) C,F,A,C,B ,E ,D 
A) C,B,A,F,D,E 
B) C,E,D,C,F,A,B 
C) A,C ,D ,E ,F ,B 
D) D,F,A,C,B,E 
E) C,F,A,C,B ,E ,D

Question 13

Recombinant forms of the enzyme urate oxidase are available for therapeutic purposes.Based on the information in this chapter,in which of the following conditions might this therapy be useful?

Accepted Answer

A) myoadenylate deaminase deficiency 
B) severe combined immunodeficiency disease 
C) gout 
D) toxoplasmosis 
E) folate deficiency 
A) myoadenylate deaminase deficiency 
B) severe combined immunodeficiency disease 
C) gout 
D) toxoplasmosis 
E) folate deficiency

Question 14

A final common product from both purine degradation and pyrimidine degradation is

Accepted Answer

A) uric acid. 
B) aspartate. 
C) ribose-1-phosphate. 
D) ribose-5-phosphate. 
E) malonyl-CoA. 
A) uric acid. 
B) aspartate. 
C) ribose-1-phosphate. 
D) ribose-5-phosphate. 
E) malonyl-CoA.

Question 15

Addition of pyrophosphate to which of the following occurs during the first step of purine biosynthesis?

Accepted Answer

A) 5-phosphoribosyl phosphate 
B) ribulose-5-phosphate 
C) ribose-5-phosphate 
D) ribose 
E) phosphribosylamine 
A) 5-phosphoribosyl phosphate 
B) ribulose-5-phosphate 
C) ribose-5-phosphate 
D) ribose 
E) phosphribosylamine

Question 16

The amino group added to the C2 position on IMP to form GMP is derived from

Accepted Answer

A) "aspartate" 
B) "aspargine" 
C) "glutamine" 
D) "$\alpha$-ketoglutarate" 
E) "arginine" 
A) "aspartate" 
B) "aspargine" 
C) "glutamine" 
D) "$\alpha$-ketoglutarate" 
E) "arginine"

Question 17

Atoms from which of the following amino acids are utilized in pyrimidine biosynthesis?
(I)glutamine
(II)glycine
(III)asparagine
(IV)aspartate

Accepted Answer

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

Question 18

Which of the following pathways produces the sugar moiety used for nucleotide synthesis?

Accepted Answer

A) glycolysis 
B) Calvin cycle 
C) pentose phosphate 
D) glycogen metabolism 
E) none of the above 
A) glycolysis 
B) Calvin cycle 
C) pentose phosphate 
D) glycogen metabolism 
E) none of the above

Question 19

Acyclovir is a derivative of which of the following?

Accepted Answer

A) a pyrimidine 
B) a purine 
C) malonic semialdehyde 
D) dihydrofolate 
E) thioredoxin 
A) a pyrimidine 
B) a purine 
C) malonic semialdehyde 
D) dihydrofolate 
E) thioredoxin

Question 20

Which of the following is not required for purine biosynthesis?
(I)aspartate
(II)glycine
(III)glutamine
(IV)formyl addition to tetrahydrofolate

Accepted Answer

A) I only 
B) II,IV 
C) II,III 
D) IV only 
E) All of the above are required. 
A) I only 
B) II,IV 
C) II,III 
D) IV only 
E) All of the above are required.

Exam 23: Nucleotide Metabolism

Orotate is synthesized from

Matching Choose the correct answer from the list.Not all the answers will be used. -The electrons used to convert an NDP to a dNDP ultimately come from ______.

In animals,elevated levels of PRPP will

Matching Choose the correct answer from the list.Not all the answers will be used. -The precursor to AMP and GMP is ______.

The symptoms of Lesch-Nyhan syndrome are caused by a deficiency of which of the following enzymes?

Matching Choose the correct answer from the list.Not all the answers will be used. -During the turnover of nucleic acids some purines can be reincorporated into nucleotides via _____ pathways.

Matching Choose the correct answer from the list.Not all the answers will be used. -In purine synthesis the byproduct released when aspartate functions as an amino group donor is ________.

Matching Choose the correct answer from the list.Not all the answers will be used. -Mechanism-based inhibitors are also called _____ substrates.

The anticancer drug methotrexate inhibits nucleotide synthesis.Which of the following explains why it also inhibits the synthesis of histidine and methionine?

The thymidylate synthase reaction is unique because

The conversion of dUMP to dTMP by thymidylate synthase requires which of the following cofactors? (I)thioredoxin (II)N5,N10-methylenetetrahydrofolate (III)S-adenosylmethionine

Rank the additions to the rings in order of formation.

Recombinant forms of the enzyme urate oxidase are available for therapeutic purposes.Based on the information in this chapter,in which of the following conditions might this therapy be useful?

A final common product from both purine degradation and pyrimidine degradation is

Addition of pyrophosphate to which of the following occurs during the first step of purine biosynthesis?

The amino group added to the C2 position on IMP to form GMP is derived from

Atoms from which of the following amino acids are utilized in pyrimidine biosynthesis? (I)glutamine (II)glycine (III)asparagine (IV)aspartate

Which of the following pathways produces the sugar moiety used for nucleotide synthesis?

Acyclovir is a derivative of which of the following?

Which of the following is not required for purine biosynthesis? (I)aspartate (II)glycine (III)glutamine (IV)formyl addition to tetrahydrofolate

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

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

The conversion of dUMP to dTMP by thymidylate synthase requires which of the following cofactors? (I)thioredoxin (II)N⁵,N¹⁰-methylenetetrahydrofolate (III)S-adenosylmethionine