Quiz on Enzyme Kinetics

Enzymes are biocatalyst that increases the speed of of a chemical reaction without  themselves undergoing any permanent chemical change. They neither used up in the reaction nor do they appear as a reaction products. Enzyme can increase reaction rate by favouring or enabling a different reaction pathway with a lower activation energy making it easier for the reaction to occur. 

Certain chemicals or factors inhibit or reduce the activities of enzyme. They are called enzyme inhibitors. Enzyme action can be inhibited in four different ways: a) competitive inhibition b) Non competitive inhibition c) Allosteric inhibition or feed back inhibition and d) Denaturation of enzymes. Read more>>
1. Which of the statements regarding enzymes is false?
Enzymes are specific
Enzymes may be used many times for a specific reaction
Enzymes are proteins that function as catalysts.
Enzymes provide activation energy for reactions.
2. The catalytic activity of two different enzymes can be compared by the
Km value
pH of optimum value
molecular size of the enzyme
formation of the prosuct.
3. The relationship between an enzyme and a reactant molecule can best be described as:
a temporary association
noncomplementary binding
one in which the enzyme is changed permanently
a permanent mutual alteration of structure.
4. The active site of an enzyme
remains rigid and does not change shape.
is found at the center of globular enzymes.
contains amino acids without sidechains.
None of these
5. The active site of an enzyme differs from an antibody-antigen binding site in that the enzyme active site
is complementary to a specific ligand.
contains amino acids without sidechains.
catalyzes a chemical reaction.
contains modified amino acids.
6. The transition state of a catalyzed reaction is
lower in energy than that of an uncatalyzed reaction
lower in energy than the reaction substrate
bound very weakly to the catalyst.
a highly-populated intermediate on the reaction pathway
7. The substrate Km in an enzyme-catalyzed reaction
is usually less than Kd, the dissociation constant.
cannot be equal to Kd
is never less than Kd
is estimated from the Y-intercept of a Lineweaver-Burk plot.
8. An allosteric inhibitor of an enzyme usually
denatures the enzyme.
causes the enzyme to work faster
binds to the active site
participates in feedback regulation.
9. An uncompetitive inhibitor of an enzyme catalyzed reaction
is without effect at saturating substrate concentration
can actually increase reaction velocity in rare cases
binds to the Michaelis complex and decreases Vmax.
All of these
10. Which of the following common drugs is not a specific enzyme inhibitor?
sulfonilamide
methotrexate
iodine
All of these
Score =
Correct answers:

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