@article {677495, title = {Physical bioenergetics: Energy fluxes, budgets, and constraints in cells}, journal = {PNAS}, volume = {118}, number = {28}, year = {2021}, abstract = {Cells are the basic units of all living matter which harness the flow of energy to drive the processes of life. While the biochemical networks involved in energy transduction are well-characterized, the energetic costs and constraints for specific cellular processes remain largely unknown. In particular, what are the energy budgets of cells? What are the constraints and limits energy flows impose on cellular processes? Do cells operate near these limits, and if so how do energetic constraints impact cellular functions? Physics has provided many tools to study nonequilibrium systems and to define physical limits, but applying these tools to cell biology remains a challenge. Physical bioenergetics, which resides at the interface of nonequilibrium physics, energy metabolism, and cell biology, seeks to understand how much energy cells are using, how they partition this energy between different cellular processes, and the associated energetic constraints. Here we review recent advances and discuss open questions and challenges in physical bioenergetics.}, author = {Xingbo Yang and Matthias Heminemannc and Howard, Jonathon and Greg Hubere and Srividya Iyer-Biswasf and Guillaume Le Treut and Lynch, Michael and Kristi L. Montooth and Daniel J. Needleman and Simone Pigolotti and Rodenfels, Jonathan and Pierre Ronceray and Sadasivan Shankar and Iman Tavassoly and hashi Thutupalli and Titov, Denis V. and Wang, Jin and Peter J. Foster} }