Questions: Which of the following statements about enzyme function is correct? None of the listed responses is correct. Enzymes can greatly speed up reactions, but they cannot change the net energy output because they cannot change the activation energy. Enzymes can change the equilibrium point of reactions, but they cannot speed up reactions because they cannot change the net energy output. Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output. Enzymes can greatly speed up reactions, but they cannot change the activation energy because they cannot change the net energy output.

The correct answer is: Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output.

Explanation for each option:

1. None of the listed responses is correct.
   This is incorrect because one of the statements accurately describes enzyme function.

2. Enzymes can greatly speed up reactions, but they cannot change the net energy output because they cannot change the activation energy.
   This is incorrect. Enzymes do change the activation energy, which is how they speed up reactions. They do not change the net energy output.

3. Enzymes can change the equilibrium point of reactions, but they cannot speed up reactions because they cannot change the net energy output.
   This is incorrect. Enzymes do not change the equilibrium point of reactions; they only speed up the rate at which equilibrium is reached.

4. Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output.
   This is correct. Enzymes lower the activation energy, allowing reactions to proceed faster, but they do not alter the equilibrium position or the net energy output of the reaction.

5. Enzymes can greatly speed up reactions, but they cannot change the activation energy because they cannot change the net energy output.
   This is incorrect. Enzymes speed up reactions by lowering the activation energy, not by changing the net energy output.

In summary, enzymes function by lowering the activation energy of reactions, thereby increasing the reaction rate without altering the equilibrium point or the net energy output.