The mitochondrial membrane potential, mtMP, is the electric part of the protonmotive force, ΔpH+.
Δψ = ΔpH+ - ΔµH+ / F
mtMP or Δψ is the potential difference across the inner mitochondrial (mt) membrane, expressed in the electric unit of volt [V]. Electric force of the mitochondrial membrane potential is the electric energy change per ‘motive’ electron or per electron moved across the transmembrane potential difference, with the number of ‘motive’ electrons expressed in the unit coulomb [C].
The chemical part of the protonmotive force, µH+ / F stems from the difference of pH across the mt-membrane. It contains a factor that bridges the gap between the electric force [J/C] and the chemical force [J/mol]. This factor is the Faraday constant, F, for conversion between electric force expressed in joules per coulomb or Volt [V=J/C] and chemical force with the unit joules per mole or Jol [Jol=J/mol],
F = 96.4853 kJol/V = 96,485.3 C/mol
Abbreviation: mtMP, Δψ [V]
Communicated by Gnaiger E 2012-10-05, edited 2016-02-06, 2017-09-05.
- » Keywords: Force and membrane potential
This information is part of O2k-technical support and open innovation.
Different methods for measurements of mt-membrane potential
- mt-Membrane potential can either be measured in the O2k-FluoRespirometer fluorometrically by using the fluorophores TMRM or Safranin, or potentiometrically with the O2k-TPP+ ISE-Module electrode by using the ion reporter TPP+. All mentioned ion indicator molecules inhibit respiration, which makes it essential to test the optimum concentration.
High-resolution respirometry and mt-membrane potential
MitoPedia topics: EAGLE