Electron bifurcation is a biological mechanism to drive a thermodynamically unfavorable redox reaction through direct coupling with an exergonic reaction. This process allows microorganisms to generate high energy reducing equivalents in order to sustain life and is often found in anaerobic metabolism, where the energy economy of the cell is poor. Recent work has revealed details of the redox energy landscapes for a variety of electron bifurcating enzymes, greatly expanding the understanding of how energy is transformed by this unique mechanism. Here we highlight the plasticity of these emerging landscapes, what is known regarding their mechanistic underpinnings, and provide a context for interpreting their biochemical activity within the physiological framework. We conclude with an outlook for propelling the field toward an integrative understanding of the impact of electron bifurcation.

电子分叉是一种通过与能级反应直接偶联来驱动热力学不利的氧化还原反应的生物学机制。该过程使微生物能够产生高能的等效能量来维持生命，并且经常在厌氧代谢中被发现，在厌氧代谢中细胞的能量经济性很差。最近的工作揭示了各种电子分叉酶的氧化还原能量分布的细节，极大地扩展了人们对这种独特机制如何转化能量的理解。在这里，我们重点介绍这些新兴景观的可塑性，了解其机理基础，并为在生理框架内解释其生化活性提供背景。