Thermodynamic efficiency, reversibility, and degree of coupling in energy conservation by the mitochondrial respiratory chain.

ABSTRACT: The protonmotive mitochondrial respiratory chain, comprising complexes I, III and IV, transduces free energy of the electron transfer reactions to an electrochemical proton gradient across the inner mitochondrial membrane. This gradient is used to drive synthesis of ATP and ion and metabolite transport. The efficiency of energy conversion is of interest from a physiological point of view, since the energy transduction mechanisms differ fundamentally between the three complexes. Here, we have chosen actively phosphorylating mitochondria as the focus of analysis. For all three complexes we find that the thermodynamic efficiency is about 80-90% and that the degree of coupling between the redox and proton translocation reactions is very high during active ATP synthesis. However, when net ATP s

SUBMITTER: Wikstrom M 

PROVIDER: S-EPMC7434914 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature