(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 […]
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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. […]
Concerted Feedback Inhibition in Metabolic Pathways: Achieving Stoichiometric End Product Balance
The correct answer is (1) K inhibits F→G and L inhibits F→H; D→E is inhibited at equal amounts of K and L. Introduction Metabolic pathways often branch to produce multiple end […]
Understanding Allosteric Regulation: Identifying Positive and Negative Effectors Through the Allosteric Constant LL
(DEC 2019 ASSAM) 55. An allosteric enzyme has two heterotropic effectors, X and Y. The allosteric constant, L for the enzyme in the absence of effector molecules is 180. For […]
Understanding Negative Cooperativity in Multi-Subunit Enzymes: Mechanism and Implications
(DEC 2006) 54. If an enzyme obeying Hills reaction shows negative cooperativity. It means (1) Binding of substrate to any one site of multi-subunit enzyme decreases affinity for other substrate […]
Understanding the Hill Equation and Hill Plot: Describing Cooperative Enzyme Kinetics
(NOV 2020-11) 53. The Hill equation and its plot describe the following enzyme kinetic behaviours A. Saturation Kinetics B. Cooperative Kinetics C. Log Vi/(Vmax — Vi) versus Log [s] D. […]
Modeling Oxygen Binding to Hemoglobin and Myoglobin: Kinetic Equations and Curve Fitting
The correct answer is (1) Myoglobin: curve A, reaction i, equations III and IV. Hemoglobin: curve B, reaction ii, equations I and II. Introduction Oxygen transport proteins in vertebrates—hemoglobin and myoglobin—exhibit […]
Interpreting Sigmoidal Kinetic Graphs: The Signature of Cooperativity in Biology
The correct answer is (1) Cooperativity. Introduction Graphs in biological kinetics and molecular interactions reveal fundamental information about the mechanism and nature of biological processes. One of the most distinctive patterns […]
Interpreting Ligand Binding Isotherms: Cooperativity and Protein Structure
The correct answer is (2) B is obtained with protein with positive cooperativity. Introduction The analysis of ligand binding isotherms provides insight into protein-ligand interactions, stoichiometry, and cooperative behavior in molecular […]


