Talk:Goldman equation

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Extended Goldman equation[edit]

I could extend the Goldman equation with a constant field equation including relative permeabilities on a number of mono- and divalent ions.


                          Dr Tom Piek
                          tompiek@tele2.nl

Please do so. I'm not sure, but beyond bivalent, just for the sake of discussion, wouldn't it be impossible to derived general a closed form expression for any N-valence ions (ie 3+/-, 4+/-, etc.)? Even to include the bivalent cases seems like a huge headache.

-Mao

The statement, "term, before the parenthesis, can be reduced to 59 log" assumes that the result will be in millivolts, correct? If I did my math right, that means that a temperature of about 297 Kelvin is "standard conditions". Why is that?

SwdshChf 17:51, 12 January 2007 (UTC)

With the conditions described (37 degrees C, monovalent ion) it comes out to ~26.7mV. 61.5mV is roughly 2.3 times larger. In my lectures my lecturer includes the 2.3 constant, and this goes for the Nernst equation too. So which is correct? The equations given by Wikipedia (which seem to contradict the numbers given by itself), or my lecturer (and the rest of the internet)?
Thanks. Nonagonal Spider (talk) 00:43, 1 June 2009 (UTC)
I added an explanation of how the first term is calculated. The 2.3 constant comes from converting the equation to use log instead of ln. JonathanWilliford (talk) 22:14, 13 September 2009 (UTC)


Why is it phrased for monovalent ions?[edit]

It looks like all you have to do is add the valence as an exponent to the terms. Why not put that form here? 137.132.250.9 (talk) 03:34, 16 July 2010 (UTC)


Explanation of variables?[edit]

I'm confused by the explanation of variables that starts with

   Em = The membrane potential...

First, I'm guessing that this set of explanations applies to the first equation (the one that starts "Em =...") and that the K-Na-Cl example was inserted later. If so, would it make sense to move the explanation of variables up, above the K-Na-Cl example?

Second, and more confusing to me, I see no explanation for the M+ and A- symbols. Maybe the M+ refers to positive ions, like the C+ in the derivation section? If so, would it make sense to stick to C+? I'm also guessing that M+ in the top equation is unrelated to M (the number of negative ionic species) in the same equation. If so, the equation would be clearer to me if it could avoid this double use of M.

As you can tell, I know nothing about the Goldman equation; I came here to learn. Maybe this makes me a good test case for the article, or maybe the presentation is clear to most people, in which case these comments can be ignored.

In any case, thanks for the work on the article. DavidHolmes0 (talk) 02:40, 13 February 2011 (UTC)


I don't understand that equation... why is the first ion (in the 'positive term part' called M? I thought M is any negative Ion. and the second ion is called A. Why A? To me it would make sense if you called the first one A and the second one B. But you call it M and A. Help! 85.127.87.168 (talk) 12:32, 1 July 2011 (UTC)

is it called M because it has something to do with the negative ions? permeability relative to the negative ion's permeability? Ryu (talk) 12:47, 1 July 2011 (UTC)

Plagiarism[edit]

Significant portions of this article are plagiarized. The plagiarized source is here: http://books.google.com/books?id=ULIPkwhQuG8C&pg=PA687&lpg=PA687&dq=goldman+special+case+nernst&source=bl&ots=jPvi1U5FJd&sig=gKPr0-FRzvdctxOV9So7IC7YmKs&hl=en&sa=X&ei=-WRGUpvKOIvW2QXY0YHwAw&ved=0CDsQ6AEwAg#v=onepage&q=goldman%20special%20case%20nernst&f=false Samer (talk) 05:20, 28 September 2013 (UTC)

What to do about it,then?Guru-45 (talk) 19:09, 9 October 2013 (UTC)
Well, as long as it's paraphrased and not straight-up plagiarized, it's OK; OTOH, parts of the plagiarized information had the added benefit of being flat-out wrong (in particular, the Nernst equation is NOT a special case of the Goldman equation). Samer (talk) 23:27, 12 October 2013 (UTC)

Spanish[edit]

Please translate the article into Spanish. --Lein03 (talk) 02:20, 23 September 2014 (UTC)


Units[edit]

There are some problems with consistency of units in the derivation section that make it difficult for people from outside this discipline to understand what's going on. I added a sentence just after the equation for the electric current density but I am not sure it is right. Even if we interpret qA as the positive or negative charge of a single ion in units of |e| this does not seem right since the valence has already been accounted for in the equation for the molar flux. I think is should just be the sign of the charge, so either +1 or -1. If that's what is meant then it should be stated clearly. PDini (talk) 17:57, 19 April 2015 (UTC)