ATP provides the energy for energy-consuming endergonic reactions, for example to power a molecular motor. The reaction is:
$$\text{ATP}+\text{H}_2\text{O}\to \text{ADP}+\text{P}_i+\text{free energy}$$
This reaction needs activation energy in order to take place. This is good because otherwise, all energy would be released immediately and it could not function as an energy storage.
Now my question: How can a molecular motor (or any other energy consuming protein) access the energy of ATP, when it gets near? In my current understanding the activation energy can not come from the molecular motor, because this needs energy, and does not provide energy.
One analogy: One has a matchstick (stored energy), and a droplet of water. You want to vaporize the water, but this is not possible without lightening the matchstick (activation energy), which the water can not provide.
But one can observe that our body can access this energy. How is this possible? And furthermore: Can the molecular motor access $\Delta G^0$, or $\Delta G^0 + \Delta G^* $?