Question 1

What are group-specific reagents?

Accepted Answer

These are compounds which will form a de

Question 2

An enzyme is optimally active at neutral pH, but activity drops off sharply if the pH is changed, This enzyme is likely to have what in the active site?

Accepted Answer

A)  the side chains of aspartate and glutamine 
B)  two histidine amino acid side chains 
C)  a glycine amino acid 
D) polar side chains 
E)  nonpolar side chains 
A)  the side chains of aspartate and glutamine 
B)  two histidine amino acid side chains 
C)  a glycine amino acid 
D) polar side chains 
E)  nonpolar side chains

Question 3

How are the types of inhibition kinetically distinguishable?

Accepted Answer

Competitive inhibition can be overcome b

Question 4

There is a key difference between an enzyme that uses a covalent catalysis mechanism and the other catalytic strategies.  What is this key difference?

Accepted Answer

For each of the other strategies of cata

Question 5

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: A molecule that is also known as a substrate analog.

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 6

What conclusion can be drawn concerning an inhibitor if the KM is the same in the presence and absence of the inhibitor?

Accepted Answer

A)  The inhibitor binds to the substrate. 
B)  The inhibitor has a structure that is not very similar to the substrate. 
C)  The inhibitor forms a reversible covalent bond with the enzyme. 
D)  The inhibitor binds to the same active site as the substrate. 
E)  The Vmax is larger in the presence of the inhibitor. 
A)  The inhibitor binds to the substrate. 
B)  The inhibitor has a structure that is not very similar to the substrate. 
C)  The inhibitor forms a reversible covalent bond with the enzyme. 
D)  The inhibitor binds to the same active site as the substrate. 
E)  The Vmax is larger in the presence of the inhibitor.

Question 7

Which of the following curves (no inhibitor, inhibitor 1, or inhibitor 2) represents the rate of reaction versus substrate concentration for a competitive and an uncompetitive inhibitor? Draw the double-reciprocal plot for each case.

Accepted Answer

Inhibitor 1 is a com

Question 8

A site directed mutagenesis converting histidine 57 of chymotrypsin to a lysine results in an inactive enzyme even though lysine has an amino group in its side chain.  Describe why the scientist may have thought this result surprising and why it wasn't.

Accepted Answer

The side group of histidine has two nitr

Exam 8: Mechanisms and Inhibitors

What are group-specific reagents?

An enzyme is optimally active at neutral pH, but activity drops off sharply if the pH is changed, This enzyme is likely to have what in the active site?

How are the types of inhibition kinetically distinguishable?

There is a key difference between an enzyme that uses a covalent catalysis mechanism and the other catalytic strategies. What is this key difference?

Choose the correct answer from the list below. Not all of the answers will be used. -____________: A molecule that is also known as a substrate analog.

What conclusion can be drawn concerning an inhibitor if the KM is the same in the presence and absence of the inhibitor?

Which of the following curves (no inhibitor, inhibitor 1, or inhibitor 2) represents the rate of reaction versus substrate concentration for a competitive and an uncompetitive inhibitor? Draw the double-reciprocal plot for each case.

A site directed mutagenesis converting histidine 57 of chymotrypsin to a lysine results in an inactive enzyme even though lysine has an amino group in its side chain. Describe why the scientist may have thought this result surprising and why it wasn't.

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

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