ELECTRO-OSMOSIS, WITH SOME APPLICATIONS TO PLANT PHYSIOLOGY

1963 ◽  
Vol 41 (6) ◽  
pp. 953-966 ◽  
Author(s):  
J. Dainty ◽  
P. C. Croghan ◽  
D. S. Fensom
Keyword(s):  
Plant Physiology ◽  
Cell Walls ◽  
Membrane Conductance ◽  
Irreversible Thermodynamics ◽  
Osmotic Pump ◽  
Biological Cell ◽  
Applied Potential ◽  
Electrokinetic Phenomena ◽  
Streaming Potentials ◽  
Electro Osmosis

General expressions for electrokinetic phenomena of relevance in biology are derived using the methods of irreversible thermodynamics and Onsager coefficients, not only for a Helmholtz-Smoluchowski model but also for a factional model and the model of Schmid. These last two models would seem to be more appropriate for biological cell membranes.Some applications of these expressions to plant physiology include the following: the pressure contribution of electro-osmosis to the turgor of Nitella or Chara cells is found to be negligible; the power used by an electro-osmotic pump can never be less than that used by a pressure mechanism; electro-osmosis may account for the present discrepancies between calculations of membrane conductance using tracer ions fluxes and those using applied potential differences; the streaming potentials developed by pressures across biological membranes would be too small to detect, but in large pores such as xylem or phloem vessels or in cell walls small pressures would result in easily measured potentials.

scholarly journals ELECTROKINETIC PHENOMENA

1931 ◽  
Vol 14 (5) ◽  
pp. 563-573 ◽  
Author(s):  
H. A. Abramson ◽  
E. B. Grossman
Keyword(s):  
Streaming Potential ◽  
Experimental Comparison ◽  
Consistent Difference ◽  
Real Difference ◽  
Electrokinetic Phenomena ◽  
Egg Albumin ◽  
Streaming Potentials ◽  
The Difference

1. The conditions are described which are necessary for the comparison of certain types of electrokinetic potentials. An experimental comparison is made of (a) electrophoresis of quartz particles covered with egg albumin; and (b) similar experiments by Briggs on streaming potentials. A slight, consistent, difference is found between the electrophoretic potential and the streaming potential. This difference is probably due to the difference in the protein preparations used rather than to real difference in the electrophoretic and streaming potentials. 2. Data are given which facilitate the measurements and enhance the precision of the estimation of electrical mobilities of microscopic particles.

Determination of transport constants of isolated Nitella cell walls

1968 ◽  
Vol 46 (4) ◽  
pp. 317-327 ◽  
Author(s):  
M. T. Tyree
Keyword(s):  
Activation Energy ◽  
Cell Wall ◽  
Diffusion Coefficient ◽  
Cell Walls ◽  
Transport Coefficients ◽  
Irreversible Thermodynamics ◽  
Kcal Mole ◽  
Limiting Value ◽  
Nitella Flexilis

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.

scholarly journals Multiscale Models in the Biomechanics of Plant Growth

Physiology ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 159-166 ◽  
Author(s):  
Oliver E. Jensen ◽  
John A. Fozard
Keyword(s):  
Plant Physiology ◽  
Plant Growth ◽  
Cell Walls ◽  
Adherent Cells ◽  
Multiscale Models ◽  
Multiple Cell

Plant growth occurs through the coordinated expansion of tightly adherent cells, driven by regulated softening of cell walls. It is an intrinsically multiscale process, with the integrated properties of multiple cell walls shaping the whole tissue. Multiscale models encode physical relationships to bring new understanding to plant physiology and development.

scholarly journals Plant Physiology: FERONIA Defends the Cell Walls against Corrosion

2018 ◽  
Vol 28 (5) ◽  
pp. R215-R217 ◽  
Author(s):  
Stéphane Verger ◽  
Olivier Hamant
Keyword(s):  
Plant Physiology ◽  
Cell Walls

THE BIO-ELECTRIC POTENTIALS OF PLANTS AND THEIR FUNCTIONAL SIGNIFICANCE: I. AN ELECTROKINETIC THEORY OF TRANSPORT

1957 ◽  
Vol 35 (4) ◽  
pp. 573-582 ◽  
Author(s):  
D. S. Fensom
Keyword(s):  
Metabolic Activity ◽  
Functional Significance ◽  
Membrane Diffusion ◽  
Streaming Potentials ◽  
Electro Osmosis ◽  
Electric Potentials ◽  
Electrical Theory ◽  
The Way

The background of bio-potentials in relation to transport is briefly reviewed and the chief difficulties lying in the way of an electrical theory of transport are pointed out. A re-examination of electro-osmosis and streaming potentials in xylem and phloem vessels suggests that the bio-electrical forces are sufficiently large in magnitude to cause transport and that they certainly operate in a direction to assist it. The productions of the potentials through metabolic activity and membrane diffusion is discussed.

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