(JUNE 2002) 66. Which of following is true for non-competitive inhibition? (1) Increases Vmax (2) Decreases Vmax (3) Increases Km (4) Decreases Km The correct answer is (2) Decreases Vmax. Introduction […]
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Noncompetitive Enzyme Inhibition: Reaction Schemes, Mechanism, and Impact on Kinetics
The correct answer is (2) E+S ⇄ ES → E+P; ES+I ⇄ ESI. Introduction Noncompetitive inhibition is a fundamental model in enzyme kinetics, describing how inhibitors can reduce enzyme activity regardless […]
Understanding Competitive Inhibition: How Substrate Concentration Overcomes Inhibition
(DEC 2001) 64. False statement of competitive inhibition is- (1) Structure same as substrate (2) Inhibits substrate binding (3) Binds to active site (4) Reaction cannot be favorably biased by […]
Understanding Enzyme Inhibition: Why Competitive Inhibition Increases KmKm but Not VmaxVmax
(JUNE 2004) 63. During inhibition of enzyme action Vmax remains unchanged while Km is increased. Inhibition is- (1) Competitive (2) Non-competitive (3) Un-competitive (4) Allosteric The correct answer is (1) Competitive. […]
Mechanism-Based (Suicide) Inhibition in Enzyme Catalysis: Penicillin’s Site of Action Explained
The correct answer is (2) K₂. Introduction Mechanism-based (suicide) inhibitors are among the most potent and specific enzyme inhibitors in biochemistry and pharmacology. Penicillin serves as a classical example, irreversibly inactivating […]
Covalent Enzyme Modification and Transition State Analogs: Key Mechanisms in Enzyme Inhibition
The correct answer is (4) The given brominated compound binds to triose phosphate isomerase at the active site and covalently modifies a glutamic acid residue required for enzyme activity. Introduction Enzyme […]
Enzyme Inhibition by Heavy Metals and Catalytic Activity of Monoclonal Antibodies: Clarifying Common Misconceptions
(DEC 2017) 60. Indicate the INCORRECT statement from the following: (1) Allosteric enzymes function through reversible noncovalent binding of allosteric modulators or effectors. (2) Monoclonal antibodies that catalyze hydrolysis of […]
How Reaction Products Inhibit Enzyme Catalysis: Mechanisms and Impact
(DEC 2014) 59. Reaction products inhibit catalysis in enzymes by (1) covalently binding to the enzyme. (2) altering the enzyme structure (3) occupying the active site. (4) form a complex […]
Selecting the Optimal Isozyme for Low Substrate Concentrations: Liver Enzyme Kinetics Explained
The correct answer is (1) A. Introduction Isozymes are enzyme variants catalyzing the same reaction but optimized for different tissue environments, frequently distinguished by their kinetic properties: the Michaelis constant (KmKm) […]
Correcting Misconceptions in Enzyme Kinetics: Allosteric Behavior and Enzymatic Efficiency
(JUNE 2019) 57. Choose the INCORRECT statement from the following statements made for an enzyme- catalyzed reaction (1) The kinetic properties of allosteric enzyme do not diverge from Michaelis-Menten behaviour. […]


