Allosteric Regulation Practice Questions

Question 1

What is the primary mechanism of action of 5-α reductase?

Accepted Answer

Reduction of C4-C5 double bond

Answer

Breakage of amide bond

Answer

Breakage of C-N bond

Answer

Breakage of N-N bond

Question 2

Which of the following is true about non-competitive inhibition?

Accepted Answer

Km remains same, Vmax decreases

Answer

Km increases, Vmax remains same

Answer

Km decreases, Vmax increases

Answer

Km increases, Vmax increases

Question 3

Which of the following is an example of allosteric inhibition?

Accepted Answer

Inhibition of PFK-1 by citrate

Answer

Decreased synthesis of glucokinase by glucagon

Answer

Inactivation of glycogen synthase by phosphorylation

Answer

None of the options

Question 4

Which of the following does NOT directly influence the activity of existing enzyme molecules?

Accepted Answer

Induction

Answer

Acetylation

Answer

Phosphorylation

Answer

Methylation

Question 5

Which kinetic parameter is primarily associated with enzyme specificity?

Accepted Answer

None of the options

Answer

Both

Answer

Km

Answer

Vmax

Question 6

Phosphofructokinase-1 occupies a key position in regulating glycolysis and is also subjected to feedback control. Which among the following are the allosteric activators of phosphofructokinase-1?

Accepted Answer

Fructose 2,6-bisphosphate

Answer

2,3-Bisphosphoglycerate (2,3-BPG)

Answer

Glucokinase

Answer

Phosphoenolpyruvate (PEP)

Question 7

Zinc is cofactor of which enzyme?

Accepted Answer

Carbonic anhydrase

Answer

Carboxylase

Answer

Kinase

Answer

Lysyl oxidase

Question 8

Acetyl CoA carboxylase is stimulated by all except which of the following?

Accepted Answer

Acyl CoA

Answer

ATP

Answer

Insulin

Answer

Citrate

Question 9

Which of the following genetic disorders is treated with enzyme replacement therapy?

Accepted Answer

Gaucher's disease

Answer

Krabbe's disease

Answer

Metachromatic leukodystrophy

Answer

Tay-Sachs disease

Question 10

Which statement is false about allosteric regulation?

Accepted Answer

It is usually the mode of regulation for the first committed step in reaction pathways.

Answer

Cellular response is faster with allosteric control than by controlling enzyme concentration in the cell.

Answer

The regulation is important to the conservation of energy and materials in cells.

Answer

Allosteric modulators bind non-covalently at sites other than the active site and induce conformational changes in the enzyme.

Allosteric Regulation — MCQs

Allosteric Regulation — MCQs

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