Presentaci

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Physiology and Biophysics of water and solutes
transport
Osvaldo Chara ochara_at_fmed.uba.ar ochara_at_iflysib.u
nlp.edu.ar
Departamento de Fisiología y Biofísica
(Facultad de Medicina, Universidad de Buenos
Aires), Buenos Aires, Argentina. (www.fmed.uba.ar)
Instituto de Física de Líquidos y Sistemas
Biológicos (Consejo Nacional de Investigaciones
Científicas y Técnicas, Universidad Nacional de
la Plata, Comisión de Investigaciones Científcias
de la Provincia de Buenos Aires), La Plata,
Argentina. (www.iflysib.unlp.edu.ar) CienciaNet (
www.ciencianet.com.ar)
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(No Transcript)
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The cup of coffee of Quilmes
coffee
sugar
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The cup of coffee of Quilmes
coffee
sugar
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The cup of coffee of Quilmes
coffee
sugar
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The cup of coffee of Quilmes
coffee
sugar
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Transport of water and solutes
Transport of non electrolytes Fick's laws
What did it happen?
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The phenomenological explanation
Imaginary membrane of area A and length ?x
Js
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Transport of water and solutes
Transport of non electrolytes Fick's laws
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Now let see another phenomenon How is the
solute movement across a biological membrane?
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Water solute
Water solute
A
C1
C2
?x
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Suppose that both, water and solute can move
across the membrane
we will focus on the solute transport (Be
patient we will go to study water transport in
17 min)
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Suppose that C1 gt C2
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Transport of water and solutes
Transport of non electrolytes Fick's laws
C1
C2
?x
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Now, we will measure the transport of solute from
one side to another
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Transport of water and solutes
Transport of non electrolytes Fick's laws
C1
C2
Js1?2
Js1?2
?x
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Transport of water and solutes
Transport of non electrolytes Fick's laws
Which is the highest? (Js1?2 or Js1?2)
(Remember, C1 gt C2)
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Transport of water and solutes
Transport of non electrolytes Fick's laws
C1
C2
Js1?2
Yeah!
Js1?2
?x
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Transport of water and solutes
Transport of non electrolytes Fick's laws
But what is the relation among Jss?
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Transport of water and solutes
Transport of non electrolytes Fick's laws
The beautiful expression
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Transport of water and solutes
The concept of permeability
But we must to know the length ?x of the membrane.
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Third week Bioenergetics
The concept of permeability
The researchers of physiology and biophysics
measure Js/A and ?C
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Transport of water and solutes
The concept of permeability
Then, to achieve an equality
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Transport of water and solutes
The concept of permeability
Therefore
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Transport of water and solutes
Do you remember an electrical circuit?
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Transport of water and solutes
Water solute
Water solute
A
C1
C2
?x
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Transport of water and solutes
Suppose that water can move across the membrane
Suppose that solute can not move across the
membrane
we will focus on the water transport (great!)
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Transport of water and solutes
Suppose that C1 gt C2
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Transport of water and solutes
C1
C2
?x
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Transport of water and solutes
A phenomenological law of osmosis
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Transport of water and solutes
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Transport of water and solutes
Lipidic bilayer
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Transport of water and solutes
Water channels Aquaporins
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Transport of water and solutes
Water channels Aquaporins
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Transport of water and solutes
Water channels Aquaporins
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Transport of water and solutes
Water channels Aquaporins
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Transport of water and solutes
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Transport of water and solutes
Cotransports
Na/glucose (SGLT)
Na-K-2Cl- (NKCC)
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Transport of water and solutes
Cotransporters
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Transport of water and solutes
Transport of electrolytes Nernst equation
electrolytes
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Third week Bioenergetics
Transport of electrolytes Nernst equation
electrolytes
zoom
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Transport of water and solutes
Transport of electrolytes Nernst equation
one molecule of electrolyte
zoom
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Transport of water and solutes
Transport of electrolytes Nernst equation
frictional force
Let see
electrical force
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Transport of water and solutes
Transport of electrolytes Nernst equation
The Flux
Then
Homogeneous concentration!
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Transport of water and solutes
Transport of electrolytes Nernst equation
This is the Nernst-Planck equation
The Flux
Thanks to Einstein we know that
Then
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Transport of water and solutes
Transport of electrolytes Nernst equation
In equilibrium
Then
Then
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Transport of water and solutes
Transport of electrolytes Nernst equation
Then
But
The Nernst equation!
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Third week Bioenergetics
Transport of electrolytes Nernst equation
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Transport of water and solutes
Transport of electrolytes Goldman equation
This is again the Nernst-Planck equation
Assuming
And
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Transport of water and solutes
Transport of electrolytes Goldman equation
Then
Integrating
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Transport of water and solutes
Transport of electrolytes Goldman equation
But remember
Therefore
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Transport of water and solutes
Osvaldo Chara ochara_at_fmed.uba.ar ochara_at_iflysib.un
lp.edu.ar Departamento de Fisiología y Biofísica
(Facultad de Medicina, Universidad de Buenos
Aires), Buenos Aires, Argentina. (www.fmed.uba.ar)
Instituto de Física de Líquidos y Sistemas
Biológicos (Consejo Nacional de Investigaciones
Científicas y Técnicas, Universidad Nacional de
la Plata, Comisión de Investigaciones Científcias
de la Provincia de Buenos Aires), La Plata,
Argentina. (www.iflysib.unlp.edu.ar) CienciaNet (
www.ciencianet.com.ar)