Dissecting flux balances to measure energetic costs in cell biology: techniques and challenges

TL;DR

This review discusses flux balance methods and experimental challenges in quantifying the energetic costs of cellular processes, integrating biochemical and physics approaches to improve understanding of cellular energy expenditure.

Contribution

It introduces a flux balance framework for designing and interpreting experiments on cellular energetic costs, highlighting measurement techniques and existing research.

Findings

Flux balance framework aids experimental design and interpretation

Measurement techniques enable quantification of metabolic fluxes

Prior work combines biochemistry and physics to assess energetic costs

Abstract

Life is a nonequilibrium phenomenon: metabolism provides a continuous supply of energy that drives nearly all cellular processes. However, very little is known about how much energy different cellular processes use, i.e. their energetic costs. The most direct experimental measurements of these costs involve modulating the activity of cellular processes and determining the resulting changes in energetic fluxes. In this review, we present a flux balance framework to aid in the design and interpretation of such experiments, and discuss the challenges associated with measuring the relevant metabolic fluxes. We then describe selected techniques that enable measurement of these fluxes. Finally, we review prior experimental and theoretical work that has employed techniques from biochemistry and nonequilibrium physics to determine the energetic costs of cellular processes.