An enzyme accelerates a biochemical reaction primarily by which mechanism?

• A Lowering the free energy of activation of the reaction ✓
• B Shifting the equilibrium of the reaction toward products
• C Increasing the overall free energy change of the reaction
• D Providing energy to the system through ATP hydrolysis

Explanation

Catalysts lower the activation energy barrier (delta G double dagger) by stabilising the transition state, allowing a larger fraction of substrate molecules to react. They do not alter the Gibbs free energy change or the equilibrium constant; the forward and reverse reactions are accelerated equally, so the position of equilibrium is unchanged. Option B is the classic trap: a true catalyst can never shift equilibrium, only shorten the time needed to reach it.

Reference: Lehninger Principles of Biochemistry, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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