Talk:Pyruvate decarboxylation by pyruvate dehydrogenase

Untitled
ATTN: ANYONE WITH BIOLOGICAL KNOWLEDGE!

I am a college student in BIO 223, and I would like to know if anyone reading this article can give me some feedback on whether or not any ATP is produced (in addition to the 2 acetyl molecules, the 2 NADH, & the 2 carbon dioxides) during this period of cellular respiration?
 * Not directly. But the NADH can go onto provide about 3 ATP via oxidative phosphorylation. David D. (Talk) 16:06, 31 January 2006 (UTC)

Also, does anyone know why this stage is not included in the biological courses of some professors as a major part of cellular respiration?
 * It usually is, you were never told where most of the acetyl CoA came from that enters the Krebs cycle? Another source of acetyl CoA is from beta oxidation of fatty acids. David D. (Talk) 16:06, 31 January 2006 (UTC)

Any helpful insight would be much appreciated... (Just post it under discussion & I will check back in few days to see if anyone has posted a response.) Thanks again.

Also: Are there any really detailed, informative, and reliable sites that I could visit that provide biologically pertinent information? I really need all the help I can get for this course. Thanks.
 * The best cite is Kimball's biology pages. They are up to date and by far the most accurate available. David D. (Talk) 16:06, 31 January 2006 (UTC)

Finding this page
Hopefully this page is now more findable! I have added the reaction to the end of glycolysis and will be adding it to the start of the citric acid cycle, although according to the KEGG pathway database this reaction doesn't technically belong to either pathway.

This reaction does belong in the aerobic respiration 'pathway' and is clearly linked from there.

This page is also reached by redirection from "the link reaction" and "link reaction".

The name "Oxidative decarboxylation"
I have never heard this step called Oxidative decarboxylation. The living world 4th ed. by George Johnson lists this step as "Pyruvate Oxidation", however, most texts just include it in the citric acid cycle or call it the "entry into the Kreb's cycle." I don't think that students will be able to find it under this name. Rozzychan
 * The one thing that matters is that wikipedia is consistent. I don't have a strong preference either way but agree that pyruvate decarboxylation is more specific. At present it is quite a general title that is, nevertheless, appropraite for this reaction. David D. (Talk) 18:58, 23 June 2006 (UTC)

The pathway
This pathway really needs cleaning up on wikipedia. There needs to be a page that directly links to each step in this pathway. How exactly does one do that?

Rozzychan 18:17, 23 June 2006 (UTC)

Which pathway? This is one reaction. Do you mean cellular respiration or possibly Krebs cycle? David D. (Talk) 18:54, 23 June 2006 (UTC)

Oxidative Decarboxylation
Do NOT equal oxidative decarboxylation to the pyruvate dehydrogenase reaction since there are other types of oxidative decarboxylations, for instane 2 such oxidative decarboxylation reactions are present in the Krebs cycle, namely the reactions catalyzed by isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase.

Oxidation can be through a)addition of oxygen to a substrate or b) removal of hydrogen ions from the substrate. to put it simple

more detailed it is the loss of electrons due to the 2 afore mentioned reasons.

Since most oxidation reactions involve hydrogen removal, these paricular enzymes are called dehydrogenases, as in the case of the earlier mentioned enzymes.

Oxidative decarboxylation = Decarboxylation of a substrate involving oxidation of the substrate.

In the case of these enzymes electrons from the substrate (reductant) are transfered to a coenzyme which becomes reduced (gain electrons). During this reaction the carboxyl group tends to spontaneusly deattach from the substrate yealding CO2, hence decarboxylation.

(Matthews, Van Holde, Ahern; Biochemistry, 3rd edition Addison-Wesley Publishing Company) — Preceding unsigned comment added by 87.99.20.132 (talk)


 * In response to this I have been very bold. This then leads to me wondering that it might be best to merge this page into the pyruvate dehydrogenase article? What do others think? David D. (Talk) 22:42, 13 November 2006 (UTC)


 * "Oxidation can be through a)addition of oxygen to a substrate or b)removal of hydrogen ions from the substrate" - Oxidation often involves removal of hydrogen ions from the substrate, but, just to clarify, removal of hydrogen ions does not constitute oxidation - and usually isn't oxidation. As you stated, oxidation is loss of electrons - and often during oxidation in biological systems hydrogen ions are removed (I don't know about oxidation done in the lab). --PhiJ 15:27, 6 April 2007 (UTC)

ATP - abundant in cells with low ATP, and so respiration, demand.
ATP - abundant in cells with low ATP, and so respiration, demand.

Ok so the first ATP should eaither be ADP or the second ATP should be ADP. Common biological sense would tell us that ADP would be bbundant in cells with low ATP. The "and so respiration, demanded" should probably just be removed as it is redundant. —The preceding unsigned comment was added by 143.109.134.169 (talk) 22:55, 12 February 2007 (UTC).

Merge
I strongly support David D.'s suggestions. This two article should definitely merge, since they're talking about exactly the same thing. Besides, the "pyruvate oxidation" article is written in a rather sloppy way. Now, I'm not pretty sure of the more appropriate/exact name for this reaction, but maybe someone could me some insight on it.

Also, according to the above discuss, "oxidative decarboxylation" should be a separate article rather than redirecting here, but it would involve editing it in a chemistry aspect, which I would not be able to do. Could anyone help on that?石川 08:59, 14 February 2007 (UTC)


 * I've made it into a biochemistry stub - assuming that if it was anything of important to chemists, there would be an article on it already. --PhiJ 16:00, 6 April 2007 (UTC)

I also support the merge, and would even possibly suggest another one. This article does seem to be about the pyruvate dehydrogenase complex, and probably couldn't say much apart from what should be in an article about that. Maybe the two should merge? —Preceding unsigned comment added by PhiJ (talk • contribs)
 * why not try the merge and see how it looks. I would not object. David D. (Talk) 17:15, 6 April 2007 (UTC)

I support the merge as well. Specific functions of the complex seem mostly a large intro about the complex as a whole and how these functions fit into that picture, relatively little specific to the function. Seems like those specifics would be better-served as sections or added details in a more comprehensive article about the whole complex. DMacks 20:56, 2 May 2007 (UTC)