The graph below shows the energy changes taking place as a chemical reaction progresses. If an enzyme is added, which arrows' magnitude will change? Will it increase or decrease?

Answer 1

In a chemical reaction, if an enzyme is added, it acts as a catalyst that lowers the activation energy required for the reaction to proceed. As a result, the energy changes represented by the arrows associated with the activation energy will change.

Specifically:

• The activation energy (Ea) for the forward reaction will decrease. This is typically represented by an arrow showing the difference in energy between the reactants and the transition state. The magnitude of this arrow will decrease.

• The activation energy (Ea) for the reverse reaction will also decrease, meaning that the arrow representing the energy difference between the transition state and the products will also have a decreased magnitude.

The final energy levels of the reactants and products, however, do not change due to the presence of the enzyme. This means that while the activation energies decrease, the overall energy difference between the reactants and products remains unchanged.

In summary, if an enzyme is added, the magnitudes of the activation energy arrows will decrease.