Even an exergonic reaction needs a small energy input before it can proceed. What is that input called?

1. Even exergonic reactions require a small amount of energy input before their energy-releasing steps can proceed. 2. These reactions have a net release of energy but still require some energy at the beginning. 3. That small input necessary for all chemical reactions to occur is the activation energy, also called the free energy of activation. 4. The free energy change measures the net outcome of the reaction rather than the barrier at its start. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 6 "Metabolism", section 6.2 Potential, Kinetic, Free, and Activation Energy_