Question 1

The relaxed form of an allosteric enzyme has _________ affinity for the substrates than the tense form.

Accepted Answer

A)  higher 
B)  equal 
C)  lower 
D)  no 
E)  None of the answers is correct. 
A)  higher 
B)  equal 
C)  lower 
D)  no 
E)  None of the answers is correct. A

Question 2

Which modified amino acid is found in prothrombin that allows for Ca2+ binding?

Accepted Answer

A)  acetyl lysine 
B)  phosphoserine 
C)  $\gamma$-carboxyglutamate 
D)  hydroxyproline 
E)  None of the answers is correct. 
A)  acetyl lysine 
B)  phosphoserine 
C)  $\gamma$-carboxyglutamate 
D)  hydroxyproline 
E)  None of the answers is correct. C

Question 3

Protein kinase A is activated by the binding of ________________ to specific sites on the regulatory subunit.

Accepted Answer

cAMP

Question 4

What term describes enzymes that are activated by proteolytic cleavage?

Accepted Answer

A)  phosphatases 
B)  isozymes 
C)  kinases 
D)  zymogens 
E)  apoenzymes 
A)  phosphatases 
B)  isozymes 
C)  kinases 
D)  zymogens 
E)  apoenzymes

Question 5

Aspartyl transcarbamylase catalyzes the first step in the synthesis of ______________.

Accepted Answer

The answer of Aspartyl transcarbamylase catalyzes the first step in...

Question 6

What is the dual action of thrombin?

Accepted Answer

Thrombin catalyzes the hydrolysis of fib

Question 7

Changes in ATCase conformation were detected by crystallizing the enzyme in the presence of PALA (N-(phosphonacetyl)-L-aspartate). What is PALA?

Accepted Answer

A)  a radioactive tag that binds to the subunits 
B)  a substrate analog that resembles the transition state 
C)  a fluorescent allosteric inhibitor analog 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  a radioactive tag that binds to the subunits 
B)  a substrate analog that resembles the transition state 
C)  a fluorescent allosteric inhibitor analog 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 8

How is trypsin activity turned off?

Accepted Answer

A)  by dephosphorylation 
B)  by binding an inhibitor protein 
C)  by a second cleavage 
D)  All of the answers are correct. 
E)  by dephosphorylation and binding an inhibitor protein 
A)  by dephosphorylation 
B)  by binding an inhibitor protein 
C)  by a second cleavage 
D)  All of the answers are correct. 
E)  by dephosphorylation and binding an inhibitor protein

Question 9

How does the sequential model differ from the concerted model for allosteric enzymes?

Accepted Answer

The concerted model does not allow for a

Question 10

p-Hydroxymercuribenzoate displaces Zn2+ from binding to crucial ______________ residues in ATCase.

Accepted Answer

Question 11

What regulatory mechanism relies on inhibition of the first step of the pathway by the final product of the pathway?

Accepted Answer

A)  competitive inhibition 
B)  uncompetitive inhibition 
C)  allosteric inhibition 
D)  feed-forward inhibition 
E)  feedback inhibition 
A)  competitive inhibition 
B)  uncompetitive inhibition 
C)  allosteric inhibition 
D)  feed-forward inhibition 
E)  feedback inhibition

Question 12

How does cigarette smoking relate to elastase function?

Accepted Answer

@#LAT-DLM&1-antitrypsin is a neutrophil protein th

Question 13

Blood serum analysis of ____________________________ isozymes is used in the diagnosis of a myocardial infarction.

Accepted Answer

lactate de

Question 14

Why might it have been surprising to find that CTP inhibits ATCase?

Accepted Answer

The substrates for ATCase are carbamoyl

Question 15

A regulatory mechanism that is NOT readily reversible is

Accepted Answer

A)  phosphorylation. 
B)  allosteric control. 
C)  proteolytic cleavage. 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  phosphorylation. 
B)  allosteric control. 
C)  proteolytic cleavage. 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 16

Blood clotting cascades are controlled mostly by

Accepted Answer

A)  zymogen activation. 
B)  phosphorylation. 
C)  allosteric activation. 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  zymogen activation. 
B)  phosphorylation. 
C)  allosteric activation. 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 17

The regulatory effects of substrates on allosteric enzymes are referred to as _______________ effects.

Accepted Answer

A)  homotropic 
B)  heterotropic 
C)  allotropic 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  homotropic 
B)  heterotropic 
C)  allotropic 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 18

Which of the following is an example of a zymogen?

Accepted Answer

A)  pepsinogen 
B)  procarboxypeptidase 
C)  T-form of ACTase 
D)  All of the answers are correct. 
E)  pepsinogen and procarboxypeptidase 
A)  pepsinogen 
B)  procarboxypeptidase 
C)  T-form of ACTase 
D)  All of the answers are correct. 
E)  pepsinogen and procarboxypeptidase

Question 19

Which of the following is the most crucial pathway for blood clotting?

Accepted Answer

A)  intrinsic pathway 
B)  extrinsic pathway 
C)  coagulation pathway 
D)  fibrinogen activation pathway 
E)  prothrombin activation pathway 
A)  intrinsic pathway 
B)  extrinsic pathway 
C)  coagulation pathway 
D)  fibrinogen activation pathway 
E)  prothrombin activation pathway

Question 20

A ______________ is an inactive precursor of an enzyme that is activated by a proteolytic cleavage.

Accepted Answer

zymogen or

Exam 10: Regulatory Strategies

The relaxed form of an allosteric enzyme has _________ affinity for the substrates than the tense form.

Which modified amino acid is found in prothrombin that allows for Ca2+ binding?

Protein kinase A is activated by the binding of ________________ to specific sites on the regulatory subunit.

What term describes enzymes that are activated by proteolytic cleavage?

Aspartyl transcarbamylase catalyzes the first step in the synthesis of ______________.

What is the dual action of thrombin?

Changes in ATCase conformation were detected by crystallizing the enzyme in the presence of PALA (N-(phosphonacetyl)-L-aspartate). What is PALA?

How is trypsin activity turned off?

How does the sequential model differ from the concerted model for allosteric enzymes?

p-Hydroxymercuribenzoate displaces Zn2+ from binding to crucial ______________ residues in ATCase.

What regulatory mechanism relies on inhibition of the first step of the pathway by the final product of the pathway?

How does cigarette smoking relate to elastase function?

Blood serum analysis of ____________________________ isozymes is used in the diagnosis of a myocardial infarction.

Why might it have been surprising to find that CTP inhibits ATCase?

A regulatory mechanism that is NOT readily reversible is

Blood clotting cascades are controlled mostly by

The regulatory effects of substrates on allosteric enzymes are referred to as _______________ effects.

Which of the following is an example of a zymogen?

Which of the following is the most crucial pathway for blood clotting?

A ______________ is an inactive precursor of an enzyme that is activated by a proteolytic cleavage.

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

Oxidative Phosphorylation

Catalytic 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

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

Nucleotide Biosynthesis

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

Which modified amino acid is found in prothrombin that allows for Ca²⁺ binding?

p-Hydroxymercuribenzoate displaces Zn²⁺ from binding to crucial ______________ residues in ATCase.