Question 1

Which of the following is correct regarding pyrimidine synthesis?

Accepted Answer

A) carbamoyl phosphate + PRPP aspartate + Pi + dihydroorotate 
B) carbamoyl phosphate + aspartate + quinone Orotate + Pi + H2O + reduced quinone 
C) dihydroorotate + quinone orotate + reduced quinine 
D) A and C 
E) None of the above 
A) carbamoyl phosphate + PRPP aspartate + Pi + dihydroorotate 
B) carbamoyl phosphate + aspartate + quinone Orotate + Pi + H2O + reduced quinone 
C) dihydroorotate + quinone orotate + reduced quinine 
D) A and C 
E) None of the above

Question 2

The last step in purine degradation
(I)generates hydrogen peroxide as a byproduct.
(II)utilizes molecular oxygen.
(III)is inhibited by methotrexate.
(IV)requires NAD+.

Accepted Answer

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

Question 3

The amino group added to the C6 position of IMP to form AMP is derived from

Accepted Answer

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

Question 4

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 5

John Buchanan began the elucidation of the synthesis of purine nucleotides by studying _______ excreted by pigeons fed isotopically labeled compounds.

Accepted Answer

A) "xanthine" 
B) "hypoxanthine" 
C) "uric acid" 
D) "$\beta$-alanine" 
E) "$\beta$-aminoisobutyrate" 
A) "xanthine" 
B) "hypoxanthine" 
C) "uric acid" 
D) "$\beta$-alanine" 
E) "$\beta$-aminoisobutyrate"

Question 6

Ribonecleotides   Using the diagram above,answer questions 43 - 45.C may be used to represent either or both of the atoms labeled C.
-Formate contributes to the ring at position _____.

Accepted Answer

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

Question 7

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 8

The synthesis of 5-phosphoribosylamine from PRPP is
(I)inhibited allosterically by ATP and GTP.
(II)activated by PRPP via feed forward activation.
(III)controlled by cAMP dependent phosphorylation.

Accepted Answer

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

Question 9

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

-Class I ribonucleotide reductases (RNR)contain a(n)______ prosthetic group.

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 10

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

Which of the following is correct regarding pyrimidine synthesis?

The last step in purine degradation (I)generates hydrogen peroxide as a byproduct. (II)utilizes molecular oxygen. (III)is inhibited by methotrexate. (IV)requires NAD⁺.

The amino group added to the C6 position of IMP to form AMP is derived from

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.

John Buchanan began the elucidation of the synthesis of purine nucleotides by studying _______ excreted by pigeons fed isotopically labeled compounds.

Ribonecleotides Using the diagram above,answer questions 43 - 45.C may be used to represent either or both of the atoms labeled C. -Formate contributes to the ring at position _____.

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

The synthesis of 5-phosphoribosylamine from PRPP is (I)inhibited allosterically by ATP and GTP. (II)activated by PRPP via feed forward activation. (III)controlled by cAMP dependent phosphorylation.

Matching Choose the correct answer from the list.Not all the answers will be used. -Class I ribonucleotide reductases (RNR)contain a(n)______ prosthetic group.

The symptoms of severe combined immunodeficiency syndrome (SCID)are caused by a deficiency of which of the following enzymes?

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

Exam 23: Nucleotide Metabolism

Which of the following is correct regarding pyrimidine synthesis?

The last step in purine degradation (I)generates hydrogen peroxide as a byproduct. (II)utilizes molecular oxygen. (III)is inhibited by methotrexate. (IV)requires NAD+.

The amino group added to the C6 position of IMP to form AMP is derived from

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.

John Buchanan began the elucidation of the synthesis of purine nucleotides by studying _______ excreted by pigeons fed isotopically labeled compounds.

Ribonecleotides Using the diagram above,answer questions 43 - 45.C may be used to represent either or both of the atoms labeled C. -Formate contributes to the ring at position _____.

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

The synthesis of 5-phosphoribosylamine from PRPP is (I)inhibited allosterically by ATP and GTP. (II)activated by PRPP via feed forward activation. (III)controlled by cAMP dependent phosphorylation.

Matching Choose the correct answer from the list.Not all the answers will be used. -Class I ribonucleotide reductases (RNR)contain a(n)______ prosthetic group.

The symptoms of severe combined immunodeficiency syndrome (SCID)are caused by a deficiency of which of the following enzymes?

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 last step in purine degradation (I)generates hydrogen peroxide as a byproduct. (II)utilizes molecular oxygen. (III)is inhibited by methotrexate. (IV)requires NAD⁺.

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.