Nonequilibrium Thermodynamics of Biochemical Networks: Energetics of Cellular Functions

I review recent advances in nonequilibrium thermodynamics of biochemical networks, organized around two central questions. First, why is free energy dissipation essential for enabling or enhancing biological function? Second, how do energetic costs constrain functional performance? Using several representative systems-beginning with the classical kinetic proofreading mechanism and extending to more recent examples such as accurate sensory adaptation, ultrasensitive responses, and synchronization of biochemical oscillators-I show that this framework not only provides new insights into the molecular mechanisms underlying these diverse processes but also reveals the general thermodynamic principles that govern their biological functions. I highlight the characteristic signatures of nonequilibrium behavior and the emergence of fundamental energy-performance trade-offs. This review strives to present the framework pedagogically and with sufficient technical detail to enable theory-inclined biophysicists to apply it to their own systems of interest. I conclude by proposing a nonequilibrium thermodynamic law for living systems and outlining promising directions for extending this theoretical approach to an even broader range of biological phenomena.