Talk:Dissociation constant

Untitled

In the equations depicted, the double-headed arrows should be replaced with the two-arrows-pointing-in-opposite-directions symbol (so, leftharpoondown below rightharpoon up). The equations illustrate equilibria, not resonance isomers. Is there way to make such an edit within Wikipedia? [Stefan Debbert, St. Paul, MN]

From Votes for deletion

The page is certainly decent content, however, its poorly written and the very title of the article far too vague. Furthermore, the information presented here is better shown in Acidity constant, solubility equilibrium and equilibrium constant. Theres nothing wrong inherently in the article, but I don't believe merging or any other possible solutions are appropriate. EagleFalconn 19:58, 10 Dec 2004 (UTC)

• Merge/redirect with equilibrium constant - this topic could be covered in one or two sentences there. Aerion 20:23, 10 Dec 2004 (UTC)

Well, the problem with a merge/redirect is that the term dissociation constant can refer to any number of things. It can be the solubility constant, which falls under solubility equilibrium, it could be acid dissociation constant, which is the acidity constant. The term is far too general to be any specific article, and while any dissociation constant is a subset of the equilibrium constant, they are not the same thing. EagleFalconn 16:20, 14 Dec 2004 (UTC)

Peter E. Lowrie states: To delete this page is akin to book-burning, better then to enhance the knowledge therein by editing to more accurately reflect the truth.

I learned less from the equilibrium constant than from the dissociation constant. Besides, the dissociation constant seems to be a special type of the more general equilibrium constant, just like the acid dissociation constant. I think this article would be a good place to put references to all other constants, including pK's and pH.

No need to delete

Indeed, I remember when this page was really really shabby looking. But now I think it's a great article.

Definition unclear to me

"complex AxBy breaks down into x A [...] where [A] [...] are the concentrations of A"

What does it mean concentration of A?

Is it concentration of only those A which were created by breaking down of complex AxBy, or is it concentration of all subunits of type A, including those that got into the solution from another source? These two possible interpretation may give different numbers, of course. — Preceding unsigned comment added by Clocktwibright (talk • contribs) 12:22, 17 July 2011 (UTC)

All uncombined molecules of A, from whatever source.

We probably need to spell this out someplace but I'm not sure this article is the place. Can someone who works on the whole chemical equilibrium area comment? or set a link to the appropriate place?Dankarl (talk) 15:36, 17 July 2011 (UTC)

amino acids

"For amino acids, the pK1 constant refers to its carboxyl (-COOH) group, pK2 refers to its amino (-NH3) group and the pK3 is the pK value of its side chain."

Needs work. Do we need a discussion of extrinsic and intrinsic pKs?Dankarl (talk) 11:01, 27 July 2011 (UTC)

Protein-Ligand Binding Drug Design

Hello, I work in drug design. The statement, "Therefore much pharmaceutical research is aimed at designing drugs that bind to only their target proteins (Negative Design) with high affinity (typically 0.1-10 nM) or at improving the affinity between a particular drug and its in-vivo protein target (Positive Design," bothered me a little bit. I just wasn't entirely clear where 0.1-10nM came from, and I feel like this either needs a citation or the concentration range should probably just be dropped. It may be too specific and hearsay for an encyclopedic entry. — Preceding unsigned comment added by 150.212.110.228 (talk) 19:59, 5 June 2013 (UTC)

Physical Interpretation of Km

"when $[{\ce {A}}]=K_{d}$, $[{\ce {B}}]=[{\ce {AB}}]$ or equivalently ${\tfrac {[{\ce {AB}}]}{{[{\ce {B}}]}+[{\ce {AB}}]}}={\tfrac {1}{2}}$. That is, K_d, which has the dimensions of concentration, equals the concentration of free A at which half of the total molecules of B are associated with A. "

Are these two equivalent? Should this not read when$[{\ce {a}}]=K_{d}$, $[{\ce {B}}/2]=[{\ce {AB}}]$ ... i.e. case 1.2 here: http://biowiki.ucdavis.edu/Core/Biochemistry/Binding/Reversible_Binding%3A_1._Equations_and_Curves — Preceding unsigned comment added by Holyone2 (talk • contribs) 09:35, 16 June 2016 (UTC)

This is just algebra. In the defining equation with unit exponents, substitute A for Kd, divide through by A, then A/A = 1 = B/AB multiply by AB gives B=AB. If your book shows a different result check its definition of B. Dankarl (talk) 02:24, 17 June 2016 (UTC)