First, the self-assembly can only occur in response to fuel, from which we conclude that the bilayer formation is driven by the formation of the acyl phosphate C8C6P. Nevertheless, the assembly is a co-assembly of C6P, C8, and C8C6P, as evidenced by the spin-down experiments. We hypothesize that all components co-assemble to form a bilayer with the aliphatic tails pointing inward. As the system runs out of chemical fuel, no new C8C6P is formed. Thus, with time, the C8C6P concentration decreases, which also changes the ratio of the components in the assembly-more C6P and C8 get accumulated in the structures. That shift in the ratio drives a change in the packing of the bilayer such that a bicontinuous bilayer phase that comprises mostly C6P forms. Finally, when all C8C6P is hydrolyzed, the bicontinuous bilayer phase dissolves, and the system is reset. Next, we tested whether the self-sustaining vesicles from simple building blocks could also be formed using prebiotically plausible fuels. Instead of EDC, we thus used the condensing agents 2-cyanoguanidine, cyanamide, dicyanamide, and methyl isocyanide (Figure ), all