Question 1

In de novo synthesis, the pyrimidine ring is assembled using:

Accepted Answer

A)  bicarbonate. 
B)  aspartate. 
C)  glutamine. 
D)  A and B. 
E)  A, B, and C. 
A)  bicarbonate. 
B)  aspartate. 
C)  glutamine. 
D)  A and B. 
E)  A, B, and C. E

Question 2

Why is nucleotide synthesis an important pathway for medical intervention? What types of disease could be treated using this information?

Accepted Answer

Interference of nucleotide synthesis could influence many different pathways because the nucleotides participate in so many processes. Especially important would be interference in the synthesis of nucleic acids to minimize or disrupt cell division, a strategy employed in cancer therapy.

Question 3

Dihydrofolate reductase is an excellent target for anticancer drugs because it is critical in the synthesis of __________________.

Accepted Answer

thymidylate

Question 4

What is the disadvantage of methotrexate as a therapeutic agent?

Accepted Answer

Methotrexate kills all rapidly growing c

Question 5

Use the following to answer questions 
Choose the correct answer from the list below. Not all of the answers will be used.
-A purine or pyrimidine base linked to a sugar and to a phosphate ester is a(n) _________________.

Accepted Answer

A) de novo 
B) xanthylate 
C) riboflavin 
D) amino acids 
E) UTP
F)N5, N10-methylenetetrahydrofolate
G)nucleotide
H)gout
I)nucleoside
J)ATP
K)urate
L)salvage 
A) de novo 
B) xanthylate 
C) riboflavin 
D) amino acids 
E) UTP
F)N5, N10-methylenetetrahydrofolate
G)nucleotide
H)gout
I)nucleoside
J)ATP
K)urate
L)salvage

Question 6

Which vitamin supplement is taken during the first trimester of pregnancy to prevent the birth defect known as spina bifida?

Accepted Answer

Spina bifida is characterized by the inc

Question 7

Hypoxanthine-guanine phosphoribosyltransferase catalyzes the formation of guanylate and __________________.

Accepted Answer

The answer of Hypoxanthine-guanine phosphoribosyltransferase catalyzes the formation of guanylate...

Question 8

TMP is made from:

Accepted Answer

A)  dTMP. 
B)  dUMP. 
C)  CTP. 
D)  ATP. 
E)  None of the above. 
A)  dTMP. 
B)  dUMP. 
C)  CTP. 
D)  ATP. 
E)  None of the above.

Question 9

In __________________ biosynthesis, the base is assembled first and then attached to ribose.

Accepted Answer

The answer of In __________________ biosynthesis, the base is assembled...

Question 10

The displacing nucleophile in pyrimidine synthesis is typically:

Accepted Answer

A)  ammonia or an amino group. 
B)  a metal ion. 
C)  coenzyme A. 
D)  All of the above. 
E)  None of the above. 
A)  ammonia or an amino group. 
B)  a metal ion. 
C)  coenzyme A. 
D)  All of the above. 
E)  None of the above.

Question 11

Some individuals with a deficiency in the enzyme adenosine deaminase exhibit __________________.

Accepted Answer

severe com

Question 12

How is ATCase, a key enzyme in pyrimidine biosynthesis, inhibited?

Accepted Answer

ATCase is inhibited by CTP, th

Question 13

Why do purine salvage pathways save the cell energy?

Accepted Answer

Free purines can be

Question 14

__________________ disease is caused by a genetic mutation resulting in the absence of hypoxanthine-guanine phosphoribosyltransferase.

Accepted Answer

The answer of __________________ disease is caused by a genetic...

Question 15

Allopurinol is used to treat gout and is an inhibitor of the enzyme(s):

Accepted Answer

A)  xanthine oxidase. 
B)  xanthine hydrolase. 
C)  hypoxanthine-guanine phosphoribosyltransferase. 
D)  All of the above. 
E)  None of the above. 
A)  xanthine oxidase. 
B)  xanthine hydrolase. 
C)  hypoxanthine-guanine phosphoribosyltransferase. 
D)  All of the above. 
E)  None of the above.

Question 16

Which enzyme carries out this reaction: XDP + YTP ↔ XTP + YDP

Accepted Answer

A)  nucleoside triphosphate kinase 
B)  nucleoside diphosphate kinase 
C)  nucleoside diphosphate phosphorylase 
D)  nucleoside triphosphate phosphorylase 
E)  None of the above. 
A)  nucleoside triphosphate kinase 
B)  nucleoside diphosphate kinase 
C)  nucleoside diphosphate phosphorylase 
D)  nucleoside triphosphate phosphorylase 
E)  None of the above.

Question 17

Which amino acid side chain in thymidylate synthase activates the ring of dUMP, making C-5 a good nucleophile?

Accepted Answer

A)  cysteine 
B)  aspartate 
C)  glutamine 
D)  tyrosine 
E)  serine 
A)  cysteine 
B)  aspartate 
C)  glutamine 
D)  tyrosine 
E)  serine

Question 18

Both de novo and salvage paths are used in the synthesis of:

Accepted Answer

A)  ribonucleotides. 
B)  deoxyribonucleotides. 
C)  dideoxyribonucleotides. 
D)  All of the above. 
E)  None of the above. 
A)  ribonucleotides. 
B)  deoxyribonucleotides. 
C)  dideoxyribonucleotides. 
D)  All of the above. 
E)  None of the above.

Question 19

What reaction actually forms the six-member ring found in pyrimidines?

Accepted Answer

The reaction between carbamoyl phosphate

Question 20

Use the following to answer questions 
Choose the correct answer from the list below. Not all of the answers will be used.
-High levels of urate cause the disease _________________.

Accepted Answer

A) de novo 
B) xanthylate 
C) riboflavin 
D) amino acids 
E) UTP
F)N5, N10-methylenetetrahydrofolate
G)nucleotide
H)gout
I)nucleoside
J)ATP
K)urate
L)salvage 
A) de novo 
B) xanthylate 
C) riboflavin 
D) amino acids 
E) UTP
F)N5, N10-methylenetetrahydrofolate
G)nucleotide
H)gout
I)nucleoside
J)ATP
K)urate
L)salvage

Exam 32: Nucleotide Metabolism

In de novo synthesis, the pyrimidine ring is assembled using:

Why is nucleotide synthesis an important pathway for medical intervention? What types of disease could be treated using this information?

Dihydrofolate reductase is an excellent target for anticancer drugs because it is critical in the synthesis of __________________.

What is the disadvantage of methotrexate as a therapeutic agent?

Use the following to answer questions Choose the correct answer from the list below. Not all of the answers will be used. -A purine or pyrimidine base linked to a sugar and to a phosphate ester is a(n) _________________.

Which vitamin supplement is taken during the first trimester of pregnancy to prevent the birth defect known as spina bifida?

Hypoxanthine-guanine phosphoribosyltransferase catalyzes the formation of guanylate and __________________.

TMP is made from:

In __________________ biosynthesis, the base is assembled first and then attached to ribose.

The displacing nucleophile in pyrimidine synthesis is typically:

Some individuals with a deficiency in the enzyme adenosine deaminase exhibit __________________.

How is ATCase, a key enzyme in pyrimidine biosynthesis, inhibited?

Why do purine salvage pathways save the cell energy?

__________________ disease is caused by a genetic mutation resulting in the absence of hypoxanthine-guanine phosphoribosyltransferase.

Allopurinol is used to treat gout and is an inhibitor of the enzyme(s):

Which enzyme carries out this reaction: XDP + YTP ↔ XTP + YDP

Which amino acid side chain in thymidylate synthase activates the ring of dUMP, making C-5 a good nucleophile?

Both de novo and salvage paths are used in the synthesis of:

What reaction actually forms the six-member ring found in pyrimidines?

Use the following to answer questions Choose the correct answer from the list below. Not all of the answers will be used. -High levels of urate cause the disease _________________.

Biochemistry and the Unity of Life

Water, Weak Bonds, and the Generation of Order Out of Chaos

Amino Acids

Protein Three-Dimensional Structure

Techniques in Protein Biochemistry

Basic Concepts of Enzyme Action

Kinetics and Regulation

Mechanisms and Inhibitors

Hemoglobin: an Allosteric Protein

Carbohydrates

Lipids

Membrane Structure and Function

Signal Transduction Pathways

Digestion: Turning a Meal Into Cellular Biochemicals

Metabolism: Basic Concepts and Design

Glycolysis

Gluconeogenesis

Preparation for the Cycle

Harvesting Electrons From the Cycle

The Electron Transport Chain

The Proton-Motive Force

The Light Reactions

The Calvin Cycle

Glycogen Degradation

Glycogen Synthesis

The Pentose Phosphate Pathway

Fatty Acid Degredation

Fatty Acid Synthesis

Lipid Synthesis

Amino Acid Degradation and the Urea Cycle

Amino Acids Synthesis

The Structure of Informational Macromolecules: Dna and Rna

DNA Replication

DNA Repair and Recombination

RNA Synthesis and Regulation in Prokaryotes

Gene Expression in Eukaryotes

RNA Processing in Eukaryotes

The Genetic Code

The Mechanism of Protein Synthesis

Recombinant Dna Techniques

Filters