In a chemical reaction, enzymes act as catalysts, which means they lower the activation energy required for the reaction to proceed. The activation energy is the energy barrier that must be overcome for reactants to convert into products.
Typically, in an energy diagram:
- Arrow A might represent the energy of the reactants.
- Arrow B often represents the activation energy or the energy change associated with the transition state.
When an enzyme is added to the reaction, it decreases the activation energy, which means the magnitude of Arrow B (activation energy) will decrease. The energy of the reactants (Arrow A) remains unchanged because the adding an enzyme does not change the inherent energies of the reactants or products.
Thus, the correct answer is: d Arrow B will decrease.