Question

unit 1 cumulative test (characteristics of life, biomolecules, cell structure and transport) 18 of 42 what is the effect of an enzyme on the energy of a chemical reaction?
○ enzymes increase the free energy of the products.
○ enzymes decrease the free energy of the reactants.
○ enzymes decrease the difference in energy between products and reactants.
○ enzymes decrease the activation energy needed for the reaction.

Explanation:

To determine the effect of an enzyme on a chemical reaction's energy, we analyze each option:

• Enzymes do not increase the free energy of products. Enzymes don't alter the free energy levels of reactants or products, so this is incorrect.
• Enzymes do not decrease the free energy of reactants. The free energy of reactants and products is a property of the reaction itself, not changed by enzymes.
• Enzymes do not decrease the energy difference between products and reactants. The difference in free energy (ΔG) between reactants and products determines if a reaction is spontaneous, and enzymes don't affect ΔG.
• Enzymes act as catalysts by lowering the activation energy required for the reaction to occur. This is the correct mechanism of how enzymes speed up reactions.

Answer:

Enzymes decrease the activation energy needed for the reaction.