Thermodynamic geometry optimisation applied to the cytochrome chain – Niels Bohr Institute - University of Copenhagen

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Thermodynamic geometry optimisation applied to the cytochrome chain

The general theory of thermodynamic geometry allows us to analyse a thermodynamic state space in the mathematical framework of metric spaces. With these mathematical tools, the Horse-Carrot theorem for thermodynamic step processes was developed, and allows us to calculate an explicit lower bound for the entropy production, and corresponding optimal states, of such a process. We will introduce a purely chemical example of such a step process optimization, based on the Electron Transport Chain (ETC) in the mitochondria.

The chain consists of three basic protein catalysed reactions, which may be analyzed using the electrochemical potential as a generalized reaction coordinate. We derive the metric structure on the corresponding thermodynamic state space and calculate the optimal electrochemical distribution of the mobile electron carriers ubiquinone and cytochrome-c. Good agreement is found between the calculated optimal configuration and consensus values in observed mitochondria under standard physiological conditions. Using the developed metric, the behavior of the ETC under variable external conditions like changing pH and changes in oxygen concentration is considered.

Vejleder: Bjarne Andresen