Question

q2
the rate of a slow metabolic reaction is sped up by the addition of a catalyst. which of the
following is a possible function of the catalyst?
1 increase the activation energy
2 increase the energy of the transition state
3 decrease the $\delta g$ value
4 increase the $\delta g$ value
5 decrease the free energy required to reach the transition state

Explanation:

To solve this, we recall the role of a catalyst: A catalyst speeds up a reaction by lowering the activation energy (the energy needed to reach the transition state). Let's analyze each option:

• Option 1: Catalysts decrease, not increase, activation energy. Eliminate.
• Option 2: Catalysts lower the energy of the transition state (by lowering activation energy), so they don't increase it. Eliminate.
• Option 3: $\Delta G$ (Gibbs free energy change) of a reaction is determined by reactants and products, not by catalysts. Catalysts don't change $\Delta G$. Eliminate.
• Option 4: Same as Option 3—catalysts don't change $\Delta G$, so they can't increase it. Eliminate.
• Option 5: By lowering the activation energy, a catalyst decreases the free energy required to reach the transition state (since activation energy is the energy needed to reach the transition state). This matches the role of a catalyst.

Answer:

1. Decrease the free energy required to reach the transition state