Reversible Inhibition Of Enzyme Activity

Question 1

What is reversible inhibition of enzyme activity?

Answer 1

A process where the binding of an inhibitor to an enzyme can be reversed, allowing the enzyme to regain its activity.

Question 2

Name the two main types of reversible inhibition.

Answer 2

Competitive inhibition and non-competitive inhibition.

Question 3

True or False: In competitive inhibition, the inhibitor binds to the active site of the enzyme.

Answer 3

True.

Question 4

Fill in the blank: In non-competitive inhibition, the inhibitor binds to a site other than the active site, known as the __________.

Answer 4

allosteric site.

Question 5

What effect does a competitive inhibitor have on the Km value of an enzyme?

Answer 5

It increases the Km value.

Question 6

What remains unchanged in non-competitive inhibition?

Answer 6

The Km value remains unchanged.

Question 7

Describe allosteric regulation of enzyme activity.

Answer 7

Allosteric regulation involves the binding of an effector molecule at a site other than the active site, which induces a conformational change in the enzyme.

Question 8

What are allosteric activators?

Answer 8

Molecules that increase the activity of an enzyme by binding to an allosteric site.

Question 9

What are allosteric inhibitors?

Answer 9

Molecules that decrease the activity of an enzyme by binding to an allosteric site.

Question 10

True or False: Allosteric enzymes typically follow Michaelis-Menten kinetics.

Answer 10

False.

Question 11

What is the shape of the curve representing allosteric enzyme kinetics?

Answer 11

Sigmoidal.

Question 12

Define feedback inhibition.

Answer 12

A regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme involved in its synthesis.

Question 13

What is an example of an allosteric enzyme?

Answer 13

Aspartate transcarbamoylase (ATCase).

Question 14

How does the presence of a substrate affect allosteric enzymes?

Answer 14

The binding of a substrate can stabilize the active form of the enzyme, increasing its activity.

Question 15

What is the role of cooperativity in allosteric enzymes?

Answer 15

Cooperativity refers to the phenomenon where the binding of a substrate to one active site affects the binding of substrates to other active sites.

Question 16

Fill in the blank: __________ is a type of inhibition where the inhibitor and substrate cannot bind simultaneously.

Answer 16

Competitive inhibition.

Question 17

What is the primary function of allosteric sites?

Answer 17

To regulate enzyme activity through the binding of effector molecules.

Question 18

True or False: Allosteric regulation can involve both positive and negative effects on enzyme activity.

Answer 18

True.

Question 19

What happens to the Vmax in non-competitive inhibition?

Answer 19

The Vmax decreases.

Question 20

Name a physiological condition that can affect enzyme activity through allosteric regulation.

Answer 20

Changes in pH or temperature.

Question 21

What is the significance of allosteric regulation in metabolic pathways?

Answer 21

It allows for fine-tuning of enzyme activity in response to changes in cellular conditions.

Question 22

Fill in the blank: An enzyme that can exist in multiple conformations is said to exhibit __________.

Answer 22

conformational flexibility.

Question 23

What is the effect of an allosteric inhibitor on the enzyme’s affinity for the substrate?

Answer 23

It decreases the enzyme’s affinity for the substrate.

Question 24

How does temperature affect enzyme activity?

Answer 24

Increased temperature typically increases activity up to a certain point, beyond which denaturation occurs.

Question 25

True or False: Enzymes can be regulated by multiple allosteric effectors simultaneously.

Answer 25

True.

Question 26

What is the main advantage of reversible inhibition in metabolic regulation?

Answer 26

It allows for quick adjustments in enzyme activity in response to changing cellular needs.