Talk:Cellular respiration

message: How does oxygen enter the mitochondria?  This page's content comes from what I've learned in high school   Biology.  Some of it may be incorrect.  Also, I'm guessing that there's just a little more that could be added.  By all means, do so (of course, that's what the 'pedia is all about). --bdesham but like who even cares.
In biochemistry I was taught that cellular respiration is a process that describes the metabolic reactions and processes that take place in a cell to obtain energy via transferring electrons to an inorganic electron acceptor, usually oxygen.  The reactions described in the "anaerobic respiration" section are not respiratory at all, rather they are fermentation reactions.  Unless things have changed in the last 10 years, glycolysis (EMP pathway) serves as the front end for both respiration (TCA cycle and electron transport system) and fermentation (transferring electrons to organic molecules resulting in things like ethanol and lactic acid).  Can others comment on the basic definition of respiration? Tokidoki25(Daisy Martinez) User Review: I thought that this article was VERY helpful, but some of the diagrams were very confusing. Rate! Review Written:December 8,2011 @ 3:23 Nbjansen 04:18, 11 March 2007 (UTC)
thread_title: Original author's note

message: Reading this article and Glycolysis, I've noticed that they duplicate a lot of information.  Should they be merged?
:I think it would be better to de-emphasise glycolysis on this page.  This page should be an overview whereas the glycolysis page should be more detailed. David D. (Talk) 20:06, 28 October 2005 (UTC)
replies: text: I agree, it's good to have separate ones. This summarizes and shows its place, glycolysis can be for more extensive detail and general interest not related to other cellular respiration processes. Tyciol 20:26, 5 October 2006 (UTC)
thread_title: Should this be merged with "Glycolysis?"

message: Shouldn't the link reaction be included here? although an apparently small step in the respiration and metabolic process it is none the less vital as without Acetyl CoA the Krebs Cycle could not occur. -Unknown
I agree, pyruvate oxidation which produces Acetyl-coA is routinely ignored for reasons I do not understand. I renumber all the standard (publishers) figures to include it as a step in respiration.  — Preceding unsigned comment added by Genesanddevelopment (talk • contribs) 01:12, 7 October 2023 (UTC)
thread_title: Link reaction

message: The actual yield is closer to 30 ATP molecules. User:69.113.3.155
:By the way i do agree that there needs to be more work the inefficency but what is the basis for that number of 30ATP's per glucose being 'normal'?  The inefficiency of the proton pumping, leakyness of the inner membrane to protons or that intermediates from glucose to CO2 are continually being syphoned off for other metabolic reactions? I'm not sure we want to put a number on this since it seems that the efficiency would vary depending on the other metabolic reactions occuring in a cell at any given time. 
:Same with the efficiency of the ETC which may vary depending on the flux through the pathway.  For example, I would imagine the efficiency would decrease during hypoxia or when ATP levels are high since the maximum PMF would be produced under those conditions. However, it may be highly efficient when a lot of oxygen and ADP are available.
:Do you have any more information? David D. (Talk) 22:50, 21 November 2005 (UTC)
replies: text: I agree; the energy charge (roughly the ratio of ATP to ADP and AMP) and availability of molecules or requirements of the cell in terms of biosynthesis, would affect how much of the glucose and its metabolites are actually shuttled into oxidative phosphorylation and ATP synthesis. Also, uncoupling proteins, e.g. UCP-1, have been found in the inner mitrochondrial membrane, and are believed to act as (tightly regulated) proton channels that allow protons to reenter the matrix, but without formation of ATP, like a sort of energy shunt. I think they are thought to play important roles in heat generation, metabolic energy processing, and are perhaps also involved in the development or control of conditions such as obesity (this article, for example, describes some of the UCP family of proteins and what their functions could be in living organisms). I also imagine that blocking the electron transport chain, removing electrons from the electron carriers, or lessening the proteins' abilities to pump protons may also reduce ATP synthesis further. Agaricus 17:34, 26 November 2006 (UTC)
thread_title: Efficiency of cellular respiration

message: In the Electron transport chain discussion pages, we noted that there are lots of pages on this subject without adequate cross-referencing. I added a See Also section to help correct this problem. -Rozzychan 18:04, 23 June 2006 (UTC)
thread_title: Added a "See also" section

message: :"Cellular respiration, involves the exchange of gasses (oxygen and carbon dioxide) between capillary beds in the systemic loop of circulatory system and the interstitial fluid of the tissues of the body."
I just deleted the sentence above since this article does not deal with this definition at all. Is there a cite for cellular respiration being a description of the extracellular gas exchange? Maybe this information is better suited to the disambiguation page? David D. (Talk) 22:52, 13 August 2006 (UTC)
thread_title: Revertion

message: I've just edited the introductory paragraph to cover respiration in a more general way (rather than simply focusing on glucose and aerobic respiration), although I'm not sure if the style of writing is unclear or not (please let me know if it is).
As for the plan, I imagine the overall goal for this article would be to describe and link to each of the major metabolic pathways involved in cell respiration, but to do this in a general, integrated fashion. So, for example, we could first describe the outline pathways of glycolysis, the Krebs Cycle and oxidative phosphorylation as the "major" respiration pathways. Then, we could consider the entry points of other carbohydrates (including glycogen), amino acids and fat breakdown products into this outline scheme. The ATP generation chart in this article is useful, but perhaps it is more suited, in its full form, to being on the Oxidative phosphorylation page instead (since it is mostly specific to that particular process, rather than to respiration in general). In the end (although I doubt I'll actually do enough editing to play a major part in it), I imagine that we'd want all of the metabolism articles organised in this way, with a general overview page that covers all the major pathways at once, with links to the topics covering each of the pathways in more detail (I think it's harder to appreciate the complexity and interlinking of metabolic pathways without considering metabolism as a whole). 
I'll start to make edits when I have the time, but if anyone else wants to do any editing, or has any suggestions to make about the "plan" I propose above, please feel free to do so. (Edit: Forgot the signature) Agaricus 20:07, 27 November 2006 (UTC)
thread_title:  Article Updating/Metabolic Integration 

message: In Aerobic respiration 38 ATP molecles are made and in anaerobic respiration 2 are made. Aerobic respiration is for multicellular organisms and anaerobic respiration is for bacteria. 2 ATP molecules would not sustain our energy needs.
:There is no scenario where 38 ATP is possible.  The two NADH from glycolysis can never be used to give 3ATP even if the whole system is running at maximum efficiency. Energy is needed to shuttle the NADH reducing energy to the ETC so electrons will not pass through complex one when glycolytic NADH is oxidised. 
:Yeast are not bacteria and use anaerobic respiration. There are plenty of aerobic microbes too. Why do you assume that 2ATP from glycolytic oxidation could not be enough energy to sustain multicellular life? David D. (Talk) 06:07, 1 December 2006 (UTC)
thread_title:  Aerobic respiration 

message: Instead of puting links to the real articles such as anerobic respiration, maybe someone should place a copy in this article.--75.28.161.31 03:59, 1 December 2006 (UTC)
replies: text: No, it would be too big.  This article is an outline of the processes involved. David D. (Talk) 06:07, 1 December 2006 (UTC)
thread_title:  Article merge 

message: Respiration (physiology) is a brief, over-arching wikipage that could accept cellular repiration quite nicely, since it overlaps it by talking about aerobic and anaerobic metabolism.  Any ideas here?  Rhetth 20:33, 21 December 2006 (UTC)
replies: text: I don't recommend it. Cellular respiration is a very large and specific subject, as any biochemistry student who has ever endured it knows very well. Really, the minute details of oxidative phosphoylation do not need to live in what should be a broader-scoped physiology article. – ClockworkSoul 23:44, 21 December 2006 (UTC)
thread_title:  Merge with respiration (physiology) ? 

message: I would like to clarify that under anaerobic respiration, you talk about a fermentation process. Note: anaerobic respiration and fermentation are two completely different processes. Anaerobic respiration is very similar to aerobic fermentation, utilizing the pyruvate decarboxylase step, entering the TCA cycle, and undergoing electron chain transport. The difference is that the final electron acceptor is a molecule other than O2. It can be a variety of molecules such as NO3-, SO42-, etc. Fermentation, on the other hand, undergoes glycolysis and then pyruvate can enter a variety of pathways, such as homolactic/heterolactic fermentation, mixed acid fermentation, and ethanol fermentation. And as for the number of ATP produced, many text books have a range from 36-38 ATP net production. And I don't agree that cellular respiration should be merged with glycolysis. Glycolysis is one of four steps in cellular respiration (4 if you count the conversion of pyruvate via pyruvate decarboxylase). Many a link can be established to glycolysis but I don't recommend merging the information.  Ambrish100 03:14, 14 March 2007 (UTC)
thread_title:  Incorrect Information 

message: It would be nice if this article were to provide information regarding the percentage of energy unlocked through respiration which can then be used by an organism - percentages would be useful.  —Preceding unsigned comment added by Save the truth (talk • contribs) 17:09, 3 September 2007 (UTC)
thread_title:  Information Regarding Useful Energy 

message: Main Article needs to turn to .68.148.164.166 (talk) 07:57, 14 January 2008 (UTC)
replies: text: Not sure I understand. What do you mean? -- Paleorthid (talk) 14:29, 14 January 2008 (UTC)

text: Thanks David D., I see now. - Paleorthid (talk) 16:32, 14 January 2008 (UTC)
thread_title:  <nowiki>==Anareobic respiration==</nowiki> 

message: In the following statement, I had changed organic, to inorganic - but there might need to be some clarification. "There are organisms, however, that can respire using other inorganic molecules as electron acceptors instead of oxygen"
I think this might be the clarification:
- For final electron acceptors in the electron transport chain in aerobic respiration, they are inorganic
- For final electron acceptors in fermentation (which can be aerobic or anaerobic), they are organic (pyruvic acid or derivatives of pyruvic acid)
Salvoland (talk) 17:22, 7 July 2008 (UTC)
replies: text: I think it is talking about lithotrophs. Tim Vickers (talk) 17:37, 7 July 2008 (UTC)
thread_title:  Inorganic vs. Organic final electron acceptors 

message: I put together this diagram for my biology class and felt that it might be of use. It may be somewhat inaccurate or unclear so please suggest any changes and I'll make them when I can. I've put it here but not added it to the article because I'm not sure where or how to fit it into the page. --RegisFrey (talk) 16:18, 16 July 2008 (UTC)
thread_title:  Diagram 

message: Hi. I'm proposing that Plant respiration be merged into here. That stub seems to be about the cellular level of things and as far as I know (not being a botanist) cellular respiration in plants is the same as in animals or indeed in most eukaryotes. I would just do it, but I'm not positive that there's not a shade of difference, so I figured I'd see if there were any objections. —Elipongo (Talk contribs) 21:13, 24 September 2008 (UTC)
replies: text: Looking at the article, I'd just turn it into a redirect to this one. There's nothing that isn't here. Tim Vickers (talk) 23:11, 24 September 2008 (UTC)
replies: text: Okay, a positive comments seems to be the only one, I'll proceed. —Elipongo (Talk contribs) 15:51, 29 September 2008 (UTC)

text: @Elipongo A non-botanist decided plant respiration is the same as that in animals? Do plants utilize fatty acids like animals? The word plant appears once in this article. I find this "Merger" misleading and/or inaccurate. I would have liked to have been able to judge the  "Plant Respiration" article on its own 24.190.31.108 (talk) 17:35, 26 May 2022 (UTC)
thread_title:  Merge with [[Plant respiration]] 

message: I have tried to balance your equation for glucose to pyruvate, with little success.  You may wish to revise your content after viewing this page.  While the general summarization of the process is correct, the end reaction only generates one proton and no water molecules.
Pdorion (talk) 10:30, 3 February 2009 (UTC)
thread_title:  Chemical equations 

message: I have recently created a table in MS-Word summarizing anaerobic and aerobic breakdown of glucose. It includes columns such as step name, reactants, products, location, and ATP yield. I think it would be useful to place it right above "See Also". How do I submit it for review?
Rhopalodia (talk) 22:53, 5 May 2009 (UTC)
replies: text: Hi there, you'll need to format it in a form that you can add here first, see Help:Table for instructions. Tim Vickers (talk) 23:37, 5 May 2009 (UTC)
thread_title:  Adding a summary table 

message: I think we need a section about the evolutionary history of this process. Kernow (talk) 03:49, 16 August 2010 (UTC)
thread_title:  Evolution 

message: I am a bit on confused when it comes to the creation of acetyl-CoA. As far as I understand, it is always created during cellular respiration as it requires oxygen to be formed from pyruvate. However, some lines also suggests that it may be created without. 
This article (Cellular Respiration) states, in the section Citric acid cycle, that:
:"When oxygen is present, acetyl-CoA is produced from the pyruvate molecules created from glycolysis. Once acetyl-CoA is formed, two processes can occur, aerobic or anaerobic respiration."
This statement suggest that acetyl-Coa is always created, with or without the required amount of oxygen to support aerobic respiration. Thus, at the same time, it also suggests that both aerobic and anaerobic respiration makes use of acetyl-CoA. 
The Wikipedia article about acetyl-CoA states that:
:"Acetyl-CoA is produced during the second step of aerobic cellular respiration, pyruvate decarboxylation, which occurs in the matrix of the mitochondria."
In the Cellular Respiration-article, in the section Aerobic respiration, it is also stated that:
:"... pyruvate enter the mitochondrion in order to be fully oxidized by the Krebs cycle."
Both these statements suggest that acetyl-CoA is created within the mitochondria. However, the acetyl-CoA-article-statement denies that acetyl-CoA is created in anaerobic respiration. 
Further down in the Cellular respiration-article, it is stated in the section Fermentation that:
:"Without oxygen, pyruvate (pyruvic acid) is not metabolized by cellular respiration but undergoes a process of fermentation. The pyruvate is not transported into the mitochondrion, but remains in the cytoplasm, where it is converted to waste products that may be removed from the cell."
This statement does not mention anything about acetyl-CoA. It does, however, deny that the pyruvate (which is made into acetyl-CoA) enters the mitochondrion. While the absence of the mitochondrion is logical in anaerobic respiration, this statement opposes the first statement of acetyl-CoA being created in both aerobic and anaerobic respiration, as acetyl-CoA is created within the mitochondrion.
What I've written here is probably messy and hard to grasp, but could anyone please try to explain this and fix any errors? This is very confusing! Sky380 (talk) 18:40, 30 November 2010 (UTC)
thread_title:  The synthesis of acetyl-CoA 

message: Correct me if I'm wrong, but isn't oxidative phosphorylation the step after the Krebs cycle? If I'm right, shouldn't it be shown as a separate step? ZFT (talk) 22:40, 15 February 2015 (UTC)
thread_title:  Table in Section 2: Efficiency of ATP production 

message: Could we please have a section discussing the fatty acid metabolism aspect of aerobic respiration? This seems to focus primarily on glycolysis. More education regarding the different effect would be useful, particularly with many considering sugar/fat diet balance or wanting to know what would happen during fasting when glycogen stores drop and the body switches to fat stores for fuel. Or in those low-carb diets. If all we talk about is pyuvate entering mitochondria then we don't get to know when fatty acids enter them. 184.145.18.50 (talk) 15:48, 3 February 2016 (UTC)
thread_title: Fatty acid discussion

message: Substituted at 11:08, 29 April 2016 (UTC)
thread_title: Assessment comment

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thread_title:  External links modified 

message: This was based on (besides rather variable experimental results) the assumption that the synthase transports 9 protons and synthesizes 3 ATP per full cycle. The actual number of protons depends on the number of c-subunits in the Fo c-ring, which varies according to organism. Since 1999 it has been known that the yeast Fo c-ring has 10 subunits (Science 286, 1700–1705 (1999).
https://www.ncbi.nlm.nih.gov/pubmed/10576729), and since 2010 that the vertebrate Fo c-ring has 8 (Bioenergetic Cost of Making an Adenosine Triphosphate Molecule in Animal Mitochondria. Watt, I.N., Montgomery, M.G., Runswick, M.J., Leslie, A.G.W., Walker, J.E. (2010) Proc.Natl.Acad.Sci.USA 107: 16823 PubMed: 20847295
https://www.ncbi.nlm.nih.gov/pubmed/20847295).  Thus in vertebrate mitochondria the cost to make an ATP, including transport reactions, is 8/3+1 or 3.67 instead of 4. The 10 protons from oxidation of NADH yield 2.73 ATP instead of 2.5, and 6 protons from oxidation of succinate yields 1.64.  These values are well within the experimental uncertainty expressed in the latest review of P/O ratios (P.Hinkle, Biochimica et Biophysica Acta 1706 (2005) 1 – 11 ) It would be good to redo this section specifying vertebrate mitochondria and using the "new" values. Eaberry (talk) 05:03, 19 March 2019 (UTC)
thread_title:  ATP synthase produces 1 ATP / 3 H+.  No! 

message: there's a little bit of repetition in the paragraph on the citric acid cycle in the aerobic respiration section at the moment
so I'd suggest it be changed to something like this for some extra clarity
sorry not everything here is going onto new lines as they should
Citric acid cycle
Main article: Citric acid cycle
This is also called the Krebs cycle or the tricarboxylic acid cycle. Acetyl-CoA is produced from the decarboxylation of the pyruvate molecules created in glycolysis. Once acetyl-CoA is formed, aerobic or anaerobic respiration can occur.[4] If oxygen is not present, fermentation of the pyruvate molecule will occur.
When oxygen is present, the mitochondria will undergo aerobic respiration which leads to the citric acid cycle. Here, acetyl-CoA is oxidized to CO2 while at the same time reducing NAD to NADH. NADH can be used by the electron transport chain to create further ATP as part of oxidative phosphorylation. To fully oxidize the equivalent of one glucose molecule, two acetyl-CoA must be metabolized by the Krebs cycle. Two waste products, H2O and CO2, are created during this cycle.
The citric acid cycle is an 8-step process involving 18 different enzymes and co-enzymes.[4] During the cycle, acetyl-CoA (2 carbons) + oxaloacetate (4 carbons) yields citrate (6 carbons), which is rearranged to a more reactive form called isocitrate (6 carbons). Isocitrate is modified to become α-ketoglutarate (5 carbons), succinyl-CoA, succinate, fumarate, malate, and, finally, oxaloacetate.
The net gain of high-energy compounds from one cycle is 3 NADH, 1 FADH2, and 1 GTP; the GTP may subsequently be used to produce ATP. Thus, the total yield from 1 glucose molecule (2 pyruvate molecules) is 6 NADH, 2 FADH2, and 2 ATP.
a clear summary similar to this would be good too:
acetyl-CoA + oxaloacetate ---> citrate.
citrate ---> isocitrate ---> α-ketoglutarate ---> succinyl-CoA ---> succinate ---> fumarate ---> malate ---> oxaloacetate  — Preceding unsigned comment added by Lucas-O'D (talk • contribs) 19:51, 4 December 2019 (UTC)
thread_title:  a little suggestion of rewording 

message: Ydsgegehje ekeeu +(ùßçœlèç: Sachidanand gupta 2007 (talk) 13:39, 25 December 2019 (UTC)
thread_title:  Sjsj 

message: Oxygen is the fundamental electron transport mechanism in the universe. Its the way through which the universe is monitoring, recording, maintaining internal stability, obtaining coordinated responses and is managing the ecology of life. Oxygen is the mediator of homeostatic regulation. The homeostatic regulation in the ecology of life is mediated through oxygen. 2402:3A80:1921:34FC:0:0:0:2 (talk) 05:02, 19 March 2021 (UTC)
replies: text: No actual edit requested. Closing this request. In the future please show exactly what you would like to add, remove or replace and provide sources. Thanks. ScottishFinnishRadish (talk) 11:03, 19 March 2021 (UTC)
thread_title:  Semi-protected edit request on 19 March 2021 

message: I would like to request to include the following content in 'Cellular Respiration'
" 
Oxygen is the fundamental electron transport mechanism in the universe. Its the way through which the universe is monitoring, recording, maintaining internal stability, obtaining coordinated responses and is managing the ecology of life. Oxygen is the mediator of homeostatic regulation. The homeostatic regulation in the ecology of life is mediated through oxygen. "
References:
1.
https://dx.doi.org/10.4172/2380-5439.S1-001
2. An insight from the ayurvedic perspective of neurodegeneration
Jibin Joy DOI:
https://doi.org/10.1016/j.parkreldis.2015.10.532 42.111.252.93 (talk) 04:32, 27 March 2021 (UTC)
replies: text: Not done: see here. --Volteer1 (talk) 10:15, 27 March 2021 (UTC)
thread_title:  Semi-protected edit request on 27 March 2021 

message: Original first line:
Cellular respiration is a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules[1] or nutrients into adenosine triphosphate (ATP)...
Change the word "convert" to "transfer the" ... 
Change "into" to "to" before "adenosine triphosphate".
Chemical energy is not converted INTO ATP. Energy is a condition of matter not a substance. 216.117.121.28 (talk) 22:12, 8 September 2021 (UTC)
replies: text: Not done for now: please establish a consensus for this alteration before using the  template. This has been open for a week and it seems there is no consensus for that change. ScottishFinnishRadish (talk) 11:08, 14 September 2021 (UTC)
thread_title:  Semi-protected edit request on 8 September 2021 

message: Rjr in 4k4 in rjrbrb4 100.35.233.243 (talk) 19:22, 16 January 2022 (UTC)
thread_title:  Enr I 5n5j4k 

message: the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and discarding, as waste products, carbon dioxide and water.  — Preceding unsigned comment added by 198.54.93.233 (talk) 14:25, 3 May 2022 (UTC)
thread_title:  Semi-protected edit request on 3 May 2022 

message: Reference [6] is a PDF of this Wikipedia article. 24.190.31.108 (talk) 17:22, 26 May 2022 (UTC)
thread_title:  Article Refers to itself 

message: Under Aerobic respiration:
“and requires pyruvate to the mitochondria”
Should probably be:
“and requires pyruvate BE TRANSPORTED to the mitochondria” Ollamh le Bitheolaíoch (talk) 16:27, 25 July 2022 (UTC)
thread_title:  Typo