Question 1

What are some of the enzymatic features that would be important?

Accepted Answer

The enzyme could be inhibited by the interaction of a potential drug at the active site or at a site that alters conformation or regulation of the enzyme. The structure of natural substrates and activators, and their binding sites, would be useful features to study for a new drug design. The binding affinity and specificity would be important, and standard enzyme assays would be used to determine the effect of the inhibitors on Kcat, KM, and Vmax.

Question 2

A ________________ inhibitor binds irreversibly to the active site of an enzyme.

Accepted Answer

suicide

Question 3

Where does cleavage of the scissile bond by chymotrypsin occur?

Accepted Answer

A)  between a his and a ser amino acid 
B)  on the N-terminal side of a phe or trp residue 
C)  on the C-terminal side of a phe or trp residue 
D)  at the N-terminal amino acid 
E)  on the C-terminal side of an arg or lys amino acid 
A)  between a his and a ser amino acid 
B)  on the N-terminal side of a phe or trp residue 
C)  on the C-terminal side of a phe or trp residue 
D)  at the N-terminal amino acid 
E)  on the C-terminal side of an arg or lys amino acid C

Question 4

How is specificity determined by chymotrypsin?

Accepted Answer

A)  by an interaction of the active site amino acids with the substrate 
B)  by a binding of the N-terminus amino acid at the active site 
C)  by a covalent binding of a his residue to the substrate 
D)  by a conformational change upon the binding of substrate 
E)  by a binding of the proper amino acid into a deep pocket on the enzyme 
A)  by an interaction of the active site amino acids with the substrate 
B)  by a binding of the N-terminus amino acid at the active site 
C)  by a covalent binding of a his residue to the substrate 
D)  by a conformational change upon the binding of substrate 
E)  by a binding of the proper amino acid into a deep pocket on the enzyme

Question 5

The metal most commonly found at the active site of metalloproteases is:

Accepted Answer

A)  zinc. 
B)  calcium. 
C)  selenium. 
D)  magnesium. 
E)  sodium. 
A)  zinc. 
B)  calcium. 
C)  selenium. 
D)  magnesium. 
E)  sodium.

Question 6

The initial reaction kinetics of some enzymes result in a quick burst of product in a short period of time followed by a slower but sustained increase in product formation over time.  What does this type of kinetic response tell an enzymologist about the mechanism of the catalysis?

Accepted Answer

These two-phase reactions (a rapid-burst

Question 7

The antibiotic penicillin is an example of a(n) ________________ inhibitor.

Accepted Answer

The answer of The antibiotic penicillin is an example of...

Question 8

You are likely to not have a(n) ________________ type of inhibitor.

Accepted Answer

The answer of You are likely to not have a(n)...

Question 9

The straight-line kinetic plot of 1/V0 versus 1/S is called a ________________.

Accepted Answer

Lineweaver

Question 10

The ________________ stabilizes the tetrahedral intermediate of the hydrolysis of a peptide bond by chymotrypsin.

Accepted Answer

The answer of The ________________ stabilizes the tetrahedral intermediate of...

Question 11

What factors should an enzymologist consider when designing an enzyme assay?

Accepted Answer

Factors an enzymologist should consider

Question 12

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: A protease enzyme with a low pH optimum.

Accepted Answer

A) hydrolysis 
B) affinity label 
C) tyrosinase 
D) chymotrypsin 
E) pepsin
F)noncompetitive
G)uncompetitive
H)heterotropic
I)approximation and orientation
J)acid-base
K)competitive 
A) hydrolysis 
B) affinity label 
C) tyrosinase 
D) chymotrypsin 
E) pepsin
F)noncompetitive
G)uncompetitive
H)heterotropic
I)approximation and orientation
J)acid-base
K)competitive

Question 13

What is an affinity label?

Accepted Answer

This is a substrate analog that is struc

Question 14

A ________________ catalytic mechanism that forces two substrates into an appropriate three-dimensional arrangement for the reaction to occur.

Accepted Answer

catalysis

Question 15

What caused a "burst" of activity followed by a steady-state reaction when chymotrypsin was studied by stop-flow techniques?

Accepted Answer

Chymotrypsin cleaves peptide b

Question 16

What is the challenge for a protease to facilitate hydrolysis of a peptide bond?

Accepted Answer

The peptide bond contains a carbonyl tha

Question 17

How is the enzyme chymotrypsin bind and hydrolyze its substrate? How does this differ from other proteases?

Accepted Answer

Chymotrypsin binds its substrate with a

Question 18

________________ inhibitor has a structure similar to the substrate and reversibly binds to the active site of the enzyme.

Accepted Answer

The answer of ________________ inhibitor has a structure similar to...

Question 19

What is the difference between KM and KM app?

Accepted Answer

The KM is the Michaelis-Menten

Question 20

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: A type of enzyme inhibitor where KM is unaltered.

Accepted Answer

A) hydrolysis 
B) affinity label 
C) tyrosinase 
D) chymotrypsin 
E) pepsin
F)noncompetitive
G)uncompetitive
H)heterotropic
I)approximation and orientation
J)acid-base
K)competitive 
A) hydrolysis 
B) affinity label 
C) tyrosinase 
D) chymotrypsin 
E) pepsin
F)noncompetitive
G)uncompetitive
H)heterotropic
I)approximation and orientation
J)acid-base
K)competitive

Exam 8: Mechanisms and Inhibitors

What are some of the enzymatic features that would be important?

A ________________ inhibitor binds irreversibly to the active site of an enzyme.

Where does cleavage of the scissile bond by chymotrypsin occur?

How is specificity determined by chymotrypsin?

The metal most commonly found at the active site of metalloproteases is:

The initial reaction kinetics of some enzymes result in a quick burst of product in a short period of time followed by a slower but sustained increase in product formation over time. What does this type of kinetic response tell an enzymologist about the mechanism of the catalysis?

The antibiotic penicillin is an example of a(n) ________________ inhibitor.

You are likely to not have a(n) ________________ type of inhibitor.

The straight-line kinetic plot of 1/V0 versus 1/S is called a ________________.

The ________________ stabilizes the tetrahedral intermediate of the hydrolysis of a peptide bond by chymotrypsin.

What factors should an enzymologist consider when designing an enzyme assay?

Choose the correct answer from the list below. Not all of the answers will be used. -____________: A protease enzyme with a low pH optimum.

What is an affinity label?

A ________________ catalytic mechanism that forces two substrates into an appropriate three-dimensional arrangement for the reaction to occur.

What caused a "burst" of activity followed by a steady-state reaction when chymotrypsin was studied by stop-flow techniques?

What is the challenge for a protease to facilitate hydrolysis of a peptide bond?

How is the enzyme chymotrypsin bind and hydrolyze its substrate? How does this differ from other proteases?

________________ inhibitor has a structure similar to the substrate and reversibly binds to the active site of the enzyme.

What is the difference between KM and KM app?

Choose the correct answer from the list below. Not all of the answers will be used. -____________: A type of enzyme inhibitor where KM is unaltered.

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

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

Nucleotide Metabolism

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

The straight-line kinetic plot of 1/V₀versus 1/S is called a ________________.

What is the difference between K_M and K_M app?