Energy transduction in chemical reaction networks: From single molecules to ecosystems
Chemical reaction networks (CRNs) are the engines of free-energy transduction, from molecular machines to ecosystems. After outlining the thermodynamic principles governing open CRNs and their ability to channel one form of free energy into another, I will introduce the concept of transduction gears and show how their performance and gear shifting can be optimized by kinetics [1]. This framework naturally extends from the case of a single input–output process to networks with multiple inputs and outputs, where a general definition of energy transduction emerges [2]. To tackle the complexity of large CRNs, I will present a circuit theory that parallels electrical network theory, enabling modular descriptions through chemical analogues of current–voltage characteristics and Kirchhoff’s laws [3]. Applications will illustrate the approach, ranging from simple model systems to metabolic CRNs.
References:
[1] M. Bilancioni and M. Esposito, “Elementary Flux Modes as CRN Gears for Free Energy Transduction”, Nature Communications 16, 5765 (2025).
[2] M. Bilancioni and M. Esposito, “Energy Transduction in Complex Networks with Multiple Resources: The Chemistry Paradigm”, J. Chem. Phys. 163, 044106 (2025).
[3] F. Avanzini, N. Freitas and M. Esposito, “Circuit Theory for Chemical Reaction Networks”, Phys. Rev. X 13, 021041 (2023)