How Life Works—A Continuous Seebeck-Peltier Transition in Cell Membrane?

Abstract

This paper develops a non-equilibrium thermodynamic approach to life, with particular regards to the membrane role. The Onsager phenomenological coefficients are introduced in order to point out the thermophysical properties of the cell systems. The fundamental role of the cell membrane electric potential is highlighted, in relation to ions and heat fluxes, pointing out the strictly relation between heat exchange and the membrane electric potential. A Seebeck-like and Peltier-like effects emerge in order to simplify the description of the heat and the ions fluxes. Life is described as a continuos transition between the Peltier-like effect to the Seebeck-like one, and viceversa.

Non-Equilibrium Thermodynamic Approach to Ca2+-Fluxes in Cancer

“…In this paper, we wish to develop a new viewpoint in the analysis of ion fluxes, recently published in [34], based on thermodynamics, with particular regards to the non-equilibrium thermodynamics. Our aim is to suggest an approach which takes into account the ion fluxes, in relation to the membrane electric potential gradient, in order to analytically describe the link between ion fluxes and membrane potential, in relation to cancer behaviour.…”

“…In order to develop a non-equilibrium thermodynamic analysis of the cell membrane, we must consider the interrelationship between the fluxes through the cell membrane (heat and ion fluxes) and the potentials at the borders of the membrane itself (temperature and electric potential). To do so, we follow the Onsager approach, by introducing the phenomenological equations [34,[58][59][60][61]]…”

“…where J e is the current density [A m −2 ], J Q is the heat flux [W m −2 ], T is the living cell temperature, and L ij are the phenomenological coefficients, such that L 12 = L 21 in the absence of magnetic fields, and L 11 ≥ 0 and L 22 ≥ 0, and L 11 L 22 − L 2 12 > 0 [34,[58][59][60][61][62][63]. The phenomenological coefficients in the Equations ( 2) are constant over the range where the linear laws hold, and they must be determined experimentally [60,64]: L 11 is named the heat conductivity, L 22 is commonly called the electrical conductivity, while L 12 and L 21 are named the cross coefficients.…”

“…), t is the time, and J i is the current density of the i-th ion. In this condition, considering the Equation ( 2), it follows that [34,58,59]…”

“…where ρ ≈ 10 3 kg m −3 is the cell density, c ≈ 4186 J kg −1 K −1 is the specific heat of the cell, α ≈ 0.023Re 0.8 Pr 0.35 λ/ R is the coefficient of convection, with λ ≈ 0.6 W m −1 K −1 conductivity, Re ≈ 0.2 the Reynolds number and Pr ≈ 0.7 the Prandtl number [66], A area of the cell membrane, V is the cell volume, and β = α dA/dV is constant. Therefore, considering Equation (2), we can obtain [34] dφ…”