Mesoscopic non-equilibrium thermodynamics and biological systems

de Groot and Mazur [1] explained how classical non-equilibrium thermodynamics can be extended to deal with internal variables; i.e. variables that are not controlled externally. The extension, called mesocopic non-equilibrium thermodynamics, can capture the non-linear nature of activated transport processes, and can also describe the coupling among mass and heat flows and chemical reactions. I show what it means for active ion transport by the Ca2+-ATPase in sarcoplasmic reticulum, and discuss the premises of the method.