Question 1

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 C

Question 2

Which of the choices correctly represents the synthesis of dTTP as represented by the following reactions?
I.dUMP + N5,N10-methylenetetrahydrofolate $\rarr$  dTMP + dihydrofolate
II.dTMP + ATP $\rarr$  dTTP + Pi
III.dUTP + H2O $\rarr$ dUMP + PPi
IV.dUTP + N5,N10-methylenetetrahydrofolate $\rarr$ dTTP + dihydrofolate

Accepted Answer

A) I $\rarr$  II $\rarr$  IV 
B) IV only 
C) III $\rarr$  IV $\rarr$  I $\rarr$  II 
D) III $\rarr$  I $\rarr$  II 
E) III $\rarr$ 0 I 
A) I $\rarr$  II $\rarr$  IV 
B) IV only 
C) III $\rarr$  IV $\rarr$  I $\rarr$  II 
D) III $\rarr$  I $\rarr$  II 
E) III $\rarr$ 0 I D

Question 3

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Deoxyribonucleotides are synthesized by ______ of the corresponding ribonucleotide's 2' carbon.

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 P

Question 4

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 5

Which of the following organisms excrete uric acid?
I.primates
II.marine invertebrates
III.insects
IV.mammals other than primates

Accepted Answer

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

Question 6

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 7

The proposed mechanism of the Class I RNR involves

Accepted Answer

A) electron transfer directly from substrate to tyrosine 122. 
B) electron transfer from substrate to various cysteine residues. 
C) an exposed tyrosine which accepts an electron from the ribosyl radical. 
D) electron donation to external reducing agents. 
E) none of the above 
A) electron transfer directly from substrate to tyrosine 122. 
B) electron transfer from substrate to various cysteine residues. 
C) an exposed tyrosine which accepts an electron from the ribosyl radical. 
D) electron donation to external reducing agents. 
E) none of the above

Question 8

The synthesis of the dNTPs required for DNA production must be controlled by ________ in order to ensure minimal ________ activity from excess of one dNTP over the other dNTPs.

Accepted Answer

A) feedback inhibition; mutagenic 
B) feed forward activation; synthesis 
C) substrate availability; mutagenesis 
D) secondary messenger systems; synthesis 
E) feed forward; mutagenic 
A) feedback inhibition; mutagenic 
B) feed forward activation; synthesis 
C) substrate availability; mutagenesis 
D) secondary messenger systems; synthesis 
E) feed forward; mutagenic

Question 9

The symptoms of severe combined immunodeficiency syndrome (SCID)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 10

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

Question 11

The disease gout is characterized by high levels of ____, which forms crystal deposits in joints and is treated by inhibition of _______.

Accepted Answer

A) uric acid; urate oxidase 
B) uric acid; xanthine oxidase 
C) urea; urate oxidase 
D) xanthine; xanthine oxidase 
E) none of the above 
A) uric acid; urate oxidase 
B) uric acid; xanthine oxidase 
C) urea; urate oxidase 
D) xanthine; xanthine oxidase 
E) none of the above

Question 12

Ribonecleotides   Using the diagram above, answer questions .C may be used to represent either or both of the atoms labeled C.
-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.

Question 13

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 14

Which of the following statements is TRUE?

Accepted Answer

A) PRPP is an effective feedback inhibitor of nucleotide synthesis. 
B) GTP serves as the energy input for AMP synthesis from IMP. 
C) Oxidation of ribosyl moieties to produce deoxynucleotides occurs at the diphosphate level. 
D) Thymidylate synthase methylates dUTP to produce dTTP. 
E) All of the above are true. 
A) PRPP is an effective feedback inhibitor of nucleotide synthesis. 
B) GTP serves as the energy input for AMP synthesis from IMP. 
C) Oxidation of ribosyl moieties to produce deoxynucleotides occurs at the diphosphate level. 
D) Thymidylate synthase methylates dUTP to produce dTTP. 
E) All of the above are true.

Question 15

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 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

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.

Question 18

Which of the following correctly describes the formation of CTP?

Accepted Answer

A) UTP + Glutamine + ATP + H2O $\rarr$ Glutamate + ADP + Pi + CTP 
B) UMP + ATP + H2O + Glutamine $\rarr$  CMP + Glutamate + ADP + Pi 
C) TTP + N5,N10-Methylenetetrahydrofolate $\rarr$  CTP + Dihydrofolate 
D) UMP + Glutamine $\rarr$ Glutamate + CTP 
E) CMP + Glutamine + ATP $\rarr$  CTP + Glutamate + ADP + Pi 
A) UTP + Glutamine + ATP + H2O $\rarr$ Glutamate + ADP + Pi + CTP 
B) UMP + ATP + H2O + Glutamine $\rarr$  CMP + Glutamate + ADP + Pi 
C) TTP + N5,N10-Methylenetetrahydrofolate $\rarr$  CTP + Dihydrofolate 
D) UMP + Glutamine $\rarr$ Glutamate + CTP 
E) CMP + Glutamine + ATP $\rarr$  CTP + Glutamate + ADP + Pi

Question 19

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 20

Individuals that do not consume adequate folic acid have serious problems with the

Accepted Answer

A) synthesis of dATP. 
B) synthesis of dCTP. 
C) synthesis of dGTP. 
D) synthesis of dTTP. 
E) all of the above 
A) synthesis of dATP. 
B) synthesis of dCTP. 
C) synthesis of dGTP. 
D) synthesis of dTTP. 
E) all of the above

Exam 23: Nucleotide Metabolism

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

Matching Choose the correct answer from the list. Not all the answers will be used. -Deoxyribonucleotides are synthesized by ______ of the corresponding ribonucleotide's 2' carbon.

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?

Which of the following organisms excrete uric acid? I.primates II.marine invertebrates III.insects IV.mammals other than primates

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

The proposed mechanism of the Class I RNR involves

The synthesis of the dNTPs required for DNA production must be controlled by ________ in order to ensure minimal ________ activity from excess of one dNTP over the other dNTPs.

The symptoms of severe combined immunodeficiency syndrome (SCID)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. -The electrons used to convert an NDP to a dNDP ultimately come from ______.

The disease gout is characterized by high levels of ____, which forms crystal deposits in joints and is treated by inhibition of _______.

Ribonecleotides Using the diagram above, answer questions .C may be used to represent either or both of the atoms labeled C. -In animals, elevated levels of PRPP will

The thymidylate synthase reaction is unique because

Which of the following statements is TRUE?

Acyclovir is a derivative of which of the following?

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

Orotate is synthesized from

Which of the following correctly describes the formation of CTP?

Rank the additions to the rings in order of formation.

Individuals that do not consume adequate folic acid have serious problems with the

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

Glycogen Metabolism and Gluconeogenesis

Glucose Catabolism

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

Translation

Regulation of Gene Expression

Filters

The synthesis of the dNTPs required for DNA production must be controlled by in order to ensure minimal activity from excess of one dNTP over the other dNTPs.

The disease gout is characterized by high levels of , which forms crystal deposits in joints and is treated by inhibition of ___.