Enzymes increase the rate of a reaction by
- A. raising the temperature of the reaction mixture
- B. lowering the activation energy of the reaction
- C. changing the equilibrium position in favour of the products
- D. supplying the energy the reaction needs
Explanation
An enzyme provides an alternative route with a lower activation energy, so a much larger fraction of molecules has enough energy to react at body temperature. It does not change the free energy difference between reactants and products, which means the equilibrium position stays exactly where it was and only the time taken to reach it falls. Enzymes supply no energy of their own.