Enzyme Inhibition: Types, Mechanisms, and Applications in Drug Design

Question 1

Which of the following is NOT a type of enzyme inhibition mechanism?

Accepted Answer

Allosteric regulation

Answer

Competitive inhibition

Answer

Non-competitive inhibition

Answer

Uncompetitive inhibition

Question 2

In competitive inhibition, where does the inhibitor bind?

Accepted Answer

Enzyme's active site

Answer

Allosteric site on the enzyme

Answer

Substrate-binding site

Answer

Anywhere on the enzyme surface

Question 3

Which of the following is an example of an irreversible enzyme inhibitor?

Accepted Answer

Cyanide

Answer

Aspirin

Answer

Statins

Answer

Warfarin

Question 4

Which example represents a feedback inhibitor?

Accepted Answer

Cholesterol

Answer

Aspirin

Answer

Methotrexate

Answer

Isoniazid

Question 5

An enzyme has a Vmax of 120 µmol/min and a Km of 5 mM. What is the substrate concentration at which the enzyme will reach half of its maximum velocity?

Accepted Answer

2.5 mM

Answer

1 mM

Answer

5 mM

Answer

10 mM

Question 6

A scientist discovers a novel compound that inhibits an enzyme in a dose-dependent manner. What does this imply?

Accepted Answer

The compound binds to the enzyme in a saturable manner

Answer

The inhibition is irreversible

Answer

The inhibition is non-specific

Answer

The compound is a competitive inhibitor

Question 7

Which of the following methods is NOT used to study enzyme inhibition?

Accepted Answer

Electrophoresis

Answer

Spectrophotometry

Answer

Enzyme assays

Answer

Molecular docking

Question 8

Which of the following is NOT a type of reversible enzyme inhibitor?

Accepted Answer

Irreversible modifier

Answer

Competitive inhibitor

Answer

Non-competitive inhibitor

Answer

Uncompetitive inhibitor

Question 9

What is a defining feature of irreversible enzyme inhibition?

Accepted Answer

Inhibitor forms a covalent bond with the enzyme

Answer

Inhibitor binds to the enzyme's active site

Answer

Inhibitor competes with the substrate

Answer

Inhibitor non-competitively interacts with the substrate

Question 10

Which of the following is an irreversible enzyme inhibitor?

Accepted Answer

Irreversible inhibitor

Answer

Competitive inhibitor

Answer

Non-competitive inhibitor

Answer

Mixed inhibitor

Question 11

Which of the following is NOT a type of enzyme inhibitor?

Accepted Answer

Allosteric Activator

Answer

Competitive inhibitor

Answer

Non-competitive inhibitor

Answer

Uncompetitive inhibitor

Question 12

Which mechanism of action is characteristic of a competitive inhibitor?

Accepted Answer

Binds to the active site of the enzyme, competing with the substrate for binding

Answer

Binds to the enzyme-substrate complex, preventing product release

Answer

Binds to an allosteric site, changing the enzyme's conformation

Question 13

Which of the following is an example of an irreversible inhibitor?

Accepted Answer

Diisopropyl fluorophosphate (DFP)

Answer

Methotrexate

Answer

Statins

Answer

Allopurinol

Question 14

What is the effect of an uncompetitive inhibitor on enzyme kinetics?

Accepted Answer

Decreases Vmax and increases Km

Answer

Decreases Vmax and decreases Km

Answer

Increases Vmax and decreases Km

Answer

Increases Vmax and increases Km

Question 15

Which enzyme is the target of the drug statins, used to lower cholesterol levels?

Accepted Answer

HMG-CoA reductase

Answer

Acetylcholinesterase

Answer

Carbonic anhydrase

Answer

Thrombin

Question 16

What is the difference between a tight-binding inhibitor and a loose-binding inhibitor?

Accepted Answer

Tight-binding inhibitors have a higher affinity for the enzyme than loose-binding inhibitors, resulting in a lower Ki

Answer

Tight-binding inhibitors are competitive inhibitors, while loose-binding inhibitors are non-competitive inhibitors

Answer

Tight-binding inhibitors are irreversible, while loose-binding inhibitors are reversible

Question 17

What is the Michaelis constant (Km) for an enzyme?

Accepted Answer

The substrate concentration at which the enzyme reaches half of its maximum velocity (Vmax)

Answer

The inhibitor concentration that reduces enzyme activity by 50%

Answer

The maximum velocity of the enzyme

Question 18

Which of the following is a potential drawback of using enzyme inhibitors as drugs?

Accepted Answer

Off-target effects due to inhibition of multiple enzymes

Answer

High cost of production

Answer

Rapid metabolism and elimination

Question 19

Which type of inhibitor directly binds to the enzyme's active site, competing with the substrate?

Accepted Answer

Competitive inhibitor

Answer

Allosteric inhibitor

Answer

Suicide inhibitor

Answer

Non-competitive inhibitor

Question 20

What is the key difference between a reversible and an irreversible inhibitor?

Accepted Answer

Reversible inhibitors can detach from the enzyme, while irreversible inhibitors form permanent bonds.

Answer

Reversible inhibitors are more specific than irreversible inhibitors.

Answer

Reversible inhibitors have a lower affinity for the enzyme than irreversible inhibitors.

Question 21

Why is studying enzyme inhibition crucial in various fields?

Accepted Answer

Enzyme inhibition studies provide insights into enzyme function, drug design, and understanding disease mechanisms.

Answer

Enzyme inhibition studies are only useful for academic research.

Question 22

Which of the following is NOT a type of enzyme inhibitor?

Accepted Answer

Allosteric Inhibitor

Answer

Non-Competitive Inhibitor

Answer

Uncompetitive Inhibitor

Answer

Competitive Inhibitor

Question 23

A competitive inhibitor binds to the:

Accepted Answer

Active site of an enzyme

Answer

Allosteric site of an enzyme

Answer

Cofactor binding site

Answer

Binding site of a substrate

Question 24

Which type of inhibition results in a non-linear Lineweaver-Burk plot?

Accepted Answer

Non-Competitive Inhibition

Answer

Uncompetitive Inhibition

Answer

Competitive Inhibition

Answer

Allosteric Inhibition

Question 25

An uncompetitive inhibitor:

Accepted Answer

Decreases the Vmax of an enzyme

Answer

Has no effect on enzyme kinetics

Answer

Increases the Km of an enzyme

Answer

Shifts the Lineweaver-Burk plot to the left

Question 26

Which of the following is a mechanism of irreversible enzyme inhibition?

Accepted Answer

Covalent modification of the enzyme

Answer

Allosteric regulation

Answer

Competitive binding with the substrate

Answer

Formation of a tight enzyme-inhibitor complex

Question 27

Which of the following factors does NOT affect enzyme inhibition?

Accepted Answer

pH

Answer

Temperature

Answer

Inhibitor concentration

Question 28

Allosteric inhibitors can exhibit which of the following characteristics?

Accepted Answer

Cooperativity

Answer

Irreversible inhibition

Answer

Competitive binding

Answer

Non-specific binding

Question 29

Which of the following is an example of a therapeutic use of enzyme inhibitors?

Accepted Answer

Statins for cholesterol reduction

Answer

Food additives for preservation

Answer

Pesticides for insect control

Question 30

Enzyme inhibition studies can provide insights into:

Accepted Answer

Enzyme structure and function

Answer

Genetic regulation

Answer

Cell signaling pathways

Answer

Microbial ecology