At the outset, we should note that there is some controversy in the field about terminology, especially the terms "fuel", describing the reagents that are used to drive reaction networks out of equilibrium, and "dissipative", referring to the dissipation of energy throughout a process that is not at equilibrium. The "fuel" metaphor in particular can be problematic because it invokes properties of macroscopic machines that are not transferable to chemical systems (please refer to a recent article from Goldup and Aprahamian 26 for a more-thorough discussion). Nevertheless, the term is widely used in the field to refer to ATP and reagents that play the same role in non-biological nonequilibrium systems, and will be used here with this caveat.