[Campbell Biology P.211] Which of the following statements is TRUE regarding the effect of a... | Practice Question

Which of the following statements is TRUE regarding the effect of an enzyme on a chemical reaction, as depicted in the provided free energy diagram Concept 8.4 ?

  • A: Enzymes increase the activation energy (EA) of the reaction.
  • B: Enzymes change the overall free energy change (ΔG) of the reaction.
  • C: Enzymes facilitate the reaction by lowering the activation energy (EA).
  • D: Enzymes are consumed during the reaction.

Explanation

The free energy diagram clearly shows that the 'Course of reaction with enzyme' curve has a lower peak lower EA compared to the 'Course of reaction without enzyme' curve, while the initial and final free energy levels and thus ΔG remain the same. Enzymes function by lowering the activation energy barrier, thereby speeding up the reaction rate without being consumed or altering the overall energy change.