to speed up the rate of reaction to reduce the loss of energy as heat to control the direction of the reaction to protect the reaction from other chemicals
I gave my students this multiple choice question: Pepsin is an enzyme that acts in the stomach for protein digestion. Which of these is most likely the main role of pepsin in this metabolic reaction?

Only one answer is correct among these 4 choices:
- to speed up the rate of reaction
- to reduce the loss of energy as heat
- to control the direction of the reaction
- to protect the reaction from other chemicals

Could you tell me which one is correct?

to speed up the rate of reaction