Difference between revisions of "Gnaiger 2018 EBEC2018"
Line 8: | Line 8: | ||
|editor=[[Gnaiger E]] | |editor=[[Gnaiger E]] | ||
|mipnetlab=AT Innsbruck Gnaiger E | |mipnetlab=AT Innsbruck Gnaiger E | ||
}} | }} | ||
== Affiliations == | == Affiliations == | ||
Line 28: | Line 21: | ||
:::# Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - [[Gnaiger_1993_Pure_Appl_Chem |Ā»Bioblast linkĀ«]] Ā | :::# Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - [[Gnaiger_1993_Pure_Appl_Chem |Ā»Bioblast linkĀ«]] Ā | ||
:::# Gnaiger E (1989) Mitochondrial respiratory control: energetics, kinetics and efficiency. In: Energy transformations in cells and organisms. Wieser W, Gnaiger E (eds), Thieme, Stuttgart:6-17. - [[Gnaiger_1989_Energy_Transformations |Ā»Bioblast linkĀ«]] | :::# Gnaiger E (1989) Mitochondrial respiratory control: energetics, kinetics and efficiency. In: Energy transformations in cells and organisms. Wieser W, Gnaiger E (eds), Thieme, Stuttgart:6-17. - [[Gnaiger_1989_Energy_Transformations |Ā»Bioblast linkĀ«]] | ||
{{Labeling | |||
|area=Respiration | |||
|topics=Flux control, Ion;substrate transport, mt-Membrane potential | |||
|couplingstates=LEAK | |||
|event=Oral | |||
|additional=MitoEAGLE | |||
}} |
Revision as of 12:13, 3 November 2018
The protonmotive force under pressure: an isomorphic analysis. |
Link: EBEC2018
Gnaiger E (2018)
Event: EBEC2018 Budapest HU
ā.. the sum of the electrical pressure difference and the osmotic pressure difference (i.e. the electrochemical potential difference) of protonsā [1] links to non-ohmic flux-force relationships between proton leak and protonmotive force (pmf). This is experimentally established, has direct consequences on mitochondrial physiology, but is theoretically little understood [2,3]. Here I distinguish pressure from potential differences (diffusion: ĪĪ¼H+ or ĪdFH+; electric: ĪĪØ or ĪelF), to explain non-ohmic flux-force relationships on the basis of four thermodynamic theorems. (1) Einsteinās diffusion equation [4] explains the concentration gradient (dc/dz) in Fickās law as the product of chemical potential gradient (the vector force and resistance determine the velocity, v, of a particle) and local concentration, c. This yields the chemical pressure gradient (vanāt Hoff): ddĪ /dz = RTādc/dz. Flux [5] is the product of v and c; c varies with force. Therefore, flux-force relationships are non-linear. (2) The pmf is not a vector force; the gradient is replaced by a pressure difference, and local concentration by a distribution function or free activity, Ī±. Flux is a function of Ī± and force, Jd = bāĪ±āĪdFB = -bāĪdĪ B [6]. (3) At ĪelF = -ĪdFH+, the diffusion pressure of protons, ĪdĪ H+ = RTāĪcH+ [Pa=Jām-3] is balanced by electric pressure, maintained by counterions of H+. Diffusional and electric pressures are isomorphic, additive, and yield protonmotive pressure (pmp). (4) The dependence of proton leak on pmf varies with ĪelF versus ĪdFH+, in agreement with experimental evidence. The flux-force relationship is concave at high mitochondrial volume fractions, but near-exponential at small mt-matrix volume ratios. Linear flux-pmp relationships imply a near-exponential dependence of the proton leak on the pmf.
ā¢ Bioblast editor: Gnaiger E
ā¢ O2k-Network Lab: AT Innsbruck Gnaiger E
Affiliations
- D. Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck
- Oroboros Instruments
- Innsbruck, Austria. - [email protected]
References
- Mitchell P (1966) Chemiosmotic coupling in oxidative and photosynthetic phosphorylation. Glynn Research, Bodmin. Biochim Biophys Acta Bioenergetics 1807:1507-38. - Ā»Bioblast linkĀ«
- Garlid KD, Beavis AD, Ratkje SK (1989) On the nature of ion leaks in energy-transducing membranes. Biochim Biophys Acta 976:109-20. - Ā»Bioblast linkĀ«
- Beard DA (2005) A biophysical model of the mitochondrial respiratory system and oxidative phosphorylation. PLOS Comput Biol 1(4):e36. - Ā»Bioblast linkĀ«
- Einstein A (1905) Ćber die von der molekularkinetischen Theorie der WƤrme geforderte Bewegung von in ruhenden FlĆ¼ssigkeiten suspendierten Teilchen. Ann Physik 4, XVII:549-60. - Ā»Bioblast linkĀ«
- Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - Ā»Bioblast linkĀ«
- Gnaiger E (1989) Mitochondrial respiratory control: energetics, kinetics and efficiency. In: Energy transformations in cells and organisms. Wieser W, Gnaiger E (eds), Thieme, Stuttgart:6-17. - Ā»Bioblast linkĀ«
Labels: MiParea: Respiration
Regulation: Flux control, Ion;substrate transport, mt-Membrane potential
Coupling state: LEAK
Event: Oral
MitoEAGLE