Question 1

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

Accepted Answer

ATCase is inhibited by CTP,the

Question 2

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

Accepted Answer

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

Question 3

The two nucleotides that can serve as energy currency in certain biomolecular paths are ATP and _______________.

Accepted Answer

The answer of The two nucleotides that can serve as...

Question 4

In de novo synthesis,the pyrimidine ring is assembled using

Accepted Answer

A)  bicarbonate. 
B)  asparagine 
C)  NH3 from glutamine. 
D)  glycine 
E)  bicarbonate and NH3 from glutamine. 
A)  bicarbonate. 
B)  asparagine 
C)  NH3 from glutamine. 
D)  glycine 
E)  bicarbonate and NH3 from glutamine.

Question 5

Allopurinol is used to treat gout and is an inhibitor of the enzyme

Accepted Answer

A)  xanthine oxidase. 
B)  xanthine hydrolase. 
C)  hypoxanthine-guanine phosphoribosyl transferase. 
D)  urate oxidase 
E)  None of the answers is correct. 
A)  xanthine oxidase. 
B)  xanthine hydrolase. 
C)  hypoxanthine-guanine phosphoribosyl transferase. 
D)  urate oxidase 
E)  None of the answers is correct.

Question 6

How many ATP molecules are necessary to make carbamoyl phosphate by carbamoyl phosphate synthetase (CPS)?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  It depends whether the reaction takes place in the cytosol or mitochondria. 
A)  1 
B)  2 
C)  3 
D)  4 
E)  It depends whether the reaction takes place in the cytosol or mitochondria.

Question 7

What is the approximate rate change when the enzyme orotidylate decarboxylase decarboxylates orotidylate to form UMP?

Accepted Answer

The reaction would rarely occu

Question 8

Which of the following is decarboxylated to form uridylate?

Accepted Answer

A)  adenylate 
B)  cytidylate 
C)  guanylate 
D)  orotidylate 
E)  None of the answers is correct. 
A)  adenylate 
B)  cytidylate 
C)  guanylate 
D)  orotidylate 
E)  None of the answers is correct.

Question 9

What is the intermediate in the conversion of inosinate to guanylate?

Accepted Answer

A)  adenylate 
B)  cytidylate 
C)  guanylate 
D)  orotidylate 
E)  xanthylate 
A)  adenylate 
B)  cytidylate 
C)  guanylate 
D)  orotidylate 
E)  xanthylate

Question 10

Some individuals with a deficiency in the enzyme adenosine deaminase exhibit _______________ (bubble boy disease).

Accepted Answer

severe com

Question 11

What 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 12

The committed step in purine nucleotide biosynthesis is the conversion of _______________ to phosphoribosylamine.

Accepted Answer

The answer of The committed step in purine nucleotide biosynthesis...

Question 13

What enzyme carries out this reaction?
UMP + ATP  $\rarr$ UDP + ADP

Accepted Answer

A)  nucleoside triphosphate kinase 
B)  nucleoside diphosphate kinase 
C)  ATP kinase 
D)  UMP kinase 
E)  None of the answers is correct. 
A)  nucleoside triphosphate kinase 
B)  nucleoside diphosphate kinase 
C)  ATP kinase 
D)  UMP kinase 
E)  None of the answers is correct.

Question 14

What is significant about the fact that E.coli ribonucleotide reductase contains two allosteric sites?

Accepted Answer

One of the sites controls the overall ac

Question 15

In addition to UTP,the synthesis of CTP from UTP requires __________

Accepted Answer

A)  glutamine and ATP. 
B)  glycine and ATP. 
C)  glutamine, ATP, and NADH. 
D)  glycine and TTP. 
E)  None of the answers is correct. 
A)  glutamine and ATP. 
B)  glycine and ATP. 
C)  glutamine, ATP, and NADH. 
D)  glycine and TTP. 
E)  None of the answers is correct.

Question 16

_______________ disease is caused by a genetic mutation resulting in the absence of hypoxanthine-guanine phosphoribosyl transferase.

Accepted Answer

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

Question 17

What is an ATP-grasp fold?

Accepted Answer

This is a protein domain that binds ATP

Question 18

A purine or pyrimidine base linked to a sugar is a _____.

Accepted Answer

A)  nucleotide 
B)  nucleoside 
C)  ribonucleotide 
D)  deoxynucleotide 
E)  None of the answers is correct. 
A)  nucleotide 
B)  nucleoside 
C)  ribonucleotide 
D)  deoxynucleotide 
E)  None of the answers is correct.

Question 19

Amination of _____ produces CTP.

Accepted Answer

A)  TTP 
B)  ATP 
C)  UTP 
D)  GTP 
E)  OTP 
A)  TTP 
B)  ATP 
C)  UTP 
D)  GTP 
E)  OTP

Question 20

What is/are the advantage or advantages of channeling intermediates by carbamoyl phosphate synthetase?

Accepted Answer

There are three distinct sites in the en

Exam 25: Nucleotide Biosynthesis

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

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

The two nucleotides that can serve as energy currency in certain biomolecular paths are ATP and _______________.

In de novo synthesis,the pyrimidine ring is assembled using

Allopurinol is used to treat gout and is an inhibitor of the enzyme

How many ATP molecules are necessary to make carbamoyl phosphate by carbamoyl phosphate synthetase (CPS)?

What is the approximate rate change when the enzyme orotidylate decarboxylase decarboxylates orotidylate to form UMP?

Which of the following is decarboxylated to form uridylate?

What is the intermediate in the conversion of inosinate to guanylate?

Some individuals with a deficiency in the enzyme adenosine deaminase exhibit _______________ (bubble boy disease).

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

The committed step in purine nucleotide biosynthesis is the conversion of _______________ to phosphoribosylamine.

What enzyme carries out this reaction? UMP + ATP →\rarr→ UDP + ADP

What is significant about the fact that E.coli ribonucleotide reductase contains two allosteric sites?

In addition to UTP,the synthesis of CTP from UTP requires __________

_______________ disease is caused by a genetic mutation resulting in the absence of hypoxanthine-guanine phosphoribosyl transferase.

What is an ATP-grasp fold?

A purine or pyrimidine base linked to a sugar is a _____.

Amination of _____ produces CTP.

What is/are the advantage or advantages of channeling intermediates by carbamoyl phosphate synthetase?

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

What enzyme carries out this reaction? UMP + ATP $\rarr$ UDP + ADP