# Talk:Mitochondrion

This article was the subject of a Wiki Education Foundation-supported course assignment, between 26 August 2021 and 2 December 2021. Further details are available on the course page. Student editor(s): PhoenyxFeatherz.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 04:19, 17 January 2022 (UTC)

It appears that many organisms, notably ciliates, have a linear, not circular, genome. I have added the word 'usually' before circular but could someone with better access than I have to the scholarly articles on the subject add some information on this (and perhaps add it to the ciliate article too? Stub Mandrel (talk) 20:19, 2 November 2017 (UTC)

Hi Stub Mandrel. This point is addressed, not on this mitochondrion page, but on its companion page about mitochondrial DNA. In the 'Circular versus linear' subsection, one can read that "In most multicellular organisms, the mtDNA – or mitogenome – is organized as a circular, covalently closed, double-stranded DNA. But in many unicellular (e.g. the ciliate Tetrahymena or the green alga Chlamydomonas reinhardtii) and in rare cases also in multicellular organisms (e.g. in some species of Cnidaria ) the mtDNA is found as linearly organized DNA ..." If you think that more information is needed, the corresponding subsection might be expanded. Manudouz (talk) 22:51, 2 November 2017 (UTC)
Thanks, in that case it may be best just to leave my 'usually' in place. Stub Mandrel (talk) 12:36, 3 November 2017 (UTC)

Here is how to explain mitochondria in language that an ordinary non-technical reader can understand. This is an explanation by a good science teacher of how to explain biology. 
One lesson that you can apply right away is that the introduction to the mitochondria article starts out by giving the exceptions. In order to understand that introduction, you'd already have to know a lot of biology -- what's a membrane? 
What's an organelle? What does "eukaryotic" mean? And it's no excuse to say that they can click on the links. First, Wikipedia style is that you should be able to understand an article without clicking on the links. Second, when you click on the link, you often wind up in an article that is just as difficult to understand.
Here's how to start: Write a simple sentence that explains the mitochondrion in language that a beginning high school biology student could understand -- without words that he or she would have to look up. If you're having trouble, see how Campbell's Biology does it. ("Mitochondria and chloroplasts are the organelles that convert energy to forms that the cells can use for work.") 
These are my notes, with some extended quotations: 
https://www.youtube.com/watch?v=6OaIdwUdSxE&t=37s 
Tyler DeWitt: Hey science teachers -- make it fun 
Feb 5, 2013
High school science teacher Tyler DeWitt was ecstatic about a lesson plan on bacteria (how cool!) -- and devastated when his students hated it. The problem was the textbook: it was impossible to understand. He delivers a rousing call for science teachers to ditch the jargon and extreme precision, and instead make science sing through stories and demonstrations. (Filmed at TEDxBeaconStreet.)
In the communication of science there is this obsession with seriousness. 
God forbid somebody have fun learning about science. 
5:26
Another problem was that the language in their textbook was truely incomprehensible. 
If we want to summarize that story I told you before we could suumarize by saying 

"These viruses can start to make more copies of themselves by slipping their DNA into a bacterium."
The way it shows up in a textbook is: 

"Bacteriophage replication is initiated through the introduction of viral nucleic acid into a bacterium."
That's great -- perfect --for 13-year-olds. 
But here's the thing. there are plenty of people in science education who would look at that and say, there is no way we could ever give that to students, because it contains some language that isn't completely accurate. 
For example, I told you that viruses have DNA. Well, a very tiny fraction of them don't. They have something called RNA instead. So a professional science writer would circle that and say, That has to go. We have to change it to something much more technical. And after a team of professional science editors went over this really simple explanation, they find fault with almost every word I use.   
And they'd have to change anything that wasn't serious enough. And they'd have to change anything that wasn't 100% perfect. Then it would be accurate. But it would be completely impossible to understand. 

"Bacteriophage replication is initiated through the introduction of viral nuclic acid into a bacterium."
--Nbauman (talk) 01:14, 28 December 2017 (UTC)

 Done Eggishorn (talk) (contrib) 22:24, 1 January 2018 (UTC)


### Hydrogenosomes
Please insert a link to Hydrogenosome into the See also section.
Hydrogenosomes are energy-producing organelles which substitute for mitochondria in some eukaryotes, in several distinct phyla. They allow for anaerobic metabolism in otherwise obligate-aerobic clades. Their relationship to mitochondria is not certain, but they have fairly clearly evolved several times, independently in different clades; their origin is probably from mitochondria by reduction.
The hydrogenosomes provide some insight into the evolution of mitochondria, in part by demonstrating that the process of reduction of the mitochondrial genome is ongoing.
Hydrogenosomes are explicitly called out as examples in the Origin and evolution section.


### Midichloria
Please insert a link to Midichloria into the See also section.
Midichloria are a recently-discovered, officially sanctioned "joke named" genus (e.g. midi-chlorians) of rare, gram-negative, non spore-forming bacteria. They are a sister clade of the Rickettsia and so provide another example of a genus presumed closely related to the proto-mitochondrial ancestor. Interestingly, they parasitize the mitochondria in the eukaryotic cells they invade. They are already included by reference to Rickettsidae in the text of Origin and evolution, and shown explicitly in the schematic phylogeny diagram.
AstroTomical (talk) 03:09, 1 January 2018 (UTC)

Hello fellow Wikipedians,
I have just modified 3 external links on Mitochondrion. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

Added archive https://web.archive.org/web/20100125062948/http://www.cytochemistry.net/Cell-biology/mitoch1.htm to http://www.cytochemistry.net/Cell-biology/mitoch1.htm
Added archive https://web.archive.org/web/20090418174136/http://bama.ua.edu/~hsmithso/class/bsc_495/mito-plastids/mito_web.html to http://bama.ua.edu/~hsmithso/class/bsc_495/mito-plastids/mito_web.html
Added archive https://web.archive.org/web/20031211051649/http://www.wadsworth.org/databank/electron/cryomito_dis2.html to http://www.wadsworth.org/databank/electron/cryomito_dis2.html
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
If you found an error with any archives or the URLs themselves, you can fix them with this tool.
Cheers.—InternetArchiveBot (Report bug) 20:34, 2 February 2018 (UTC)

This paragraph mentioned mitochondria's localization:
"Mitochondria in cells are always distributed along microtubules and the distribution of these organelles is also correlated with the endoplasmic reticulum.[67] Recent evidence suggests that vimentin, one of the components of the cytoskeleton, is also critical to the association with the cytoskeleton."
vimentin is the protein that form intermediate filament (IF), Vimentin plays a significant role in supporting and anchoring the position of the organelles in the cytosol. seems that there's intimate interactions between microtubules and vimentin. {when microtubule depolymerizers were present, vimentin reorganization occurred, once again implying a relationship between the two systems}
source:
https://en.wikipedia.org/wiki/Vimentin  — Preceding unsigned comment added by Yasir muhammed ali (talk • contribs) 14:17, 21 July 2018 (UTC) 

Note - copyvio redacted ‑‑ElHef (Meep?) 13:12, 22 August 2018 (UTC) Evilonan (talk) 11:22, 22 August 2018 (UTC)

 Not done: Wikipedia is not a vehicle for advertising. Article content needs to rely on citations from reliable, secondary sources. Further, copying text directly from another source (even with minor changes) is a copyright violation, a violation of Wikipedia's policies. ‑‑ElHef (Meep?) 13:12, 22 August 2018 (UTC)

My understanding is that thyroid hormones have an important effect on the mitochondria.  Could someone with expertise in that area add information about that to the article? 
One source: https://www.ncbi.nlm.nih.gov/pubmed/18279015
DorothyPugh (talk) 14:48, 6 December 2019 (UTC)

The inner membrane section currently says it is the site of "mitochondrial fusion and fission protein". While the inner membrane fusion protein OPA1 is located here, most of the time when we discuss "mito fusion" we are referring to the outer membrane (mediated by Mfn1 & 2, and adapters) or the mitochondrion as a whole (OMM and IMM). "Fission protein", when not further specified, refers exclusively to Drp1, which is recruited to the outer membrane. The section should therefore be modified to just say "inner membrane fusion protein". Moreover, the current reference for this section, a severely outdated edition of the Alberts textbook, is both too broad (especially since it doesn't even give the page numbers!) and likely doesn't contain the text attributed to it. My 5th edition says it "contains proteins with three types of functions: (1) those that carry out the oxidation reactions of the electron-transport chain, (2) the ATP synthase that makes ATP in the matrix, and (3) transport proteins that allow the passage of metabolites into and out of the matrix."  JoelleJay (talk) 17:07, 27 May 2020 (UTC)

Hi there anyone who's watching this page. Just a note that I'm hoping to do some major cleanup on this page at some point in the near future. In the 10 years since this article's last GA assessment, it seems like lots of information has been added somewhat willynilly and a bit of reorganization would go a long way. Several sections read as a disjointed collection of factoids (e.g. the History & Origin and evolution sections). If anyone is watching this page and interested in helping out, let me know here and perhaps we can coordinate our efforts. Thanks! Ajpolino (talk) 06:43, 10 November 2020 (UTC)

Hello, everyone; I have been studying mitochondria signaling processes and have found that they use quantum tunneling mechanisms to transfer energy enzymatically. There is no section about this on this page, and I was hoping to ask if I could add it here with several references (to start, here are a few relevant references: NCBI, NATURE, ScienceDirect, etc).
The question is whether you all think this subject would fit, as it is fairly technical and physics-heavy; I have formulae and physical descriptions that require usage of quantum techniques. I could make another page, which points to this one, which might be the best option, but I just wanted to ask and get your perspectives :)
PhoenyxFeatherz (talk) 17:01, 14 October 2021 (UTC)

I don't think that area fits in this article, as this article is the introductory overview of mitochondria, which have many technical aspects needing coverage yet must be readable by the layman, and the article is already long.  You will see that the article has many pointers to more detailed treatments in other Wikipedia articles, as by use of "Main article" lines at the top of particular sections, "See also" lines, etc.
I don't know what sort of material you are looking to add.  The three references you mention seem to address widely divergent topics; with a quick look, I don't see what unites them other than use of the word/concept "quantum".  If you think you have a good idea for a new article, you can start on a draft article: see Wikipedia:Drafts.  You should be aware that an article should have its content supported by reliable secondary sources rather than primary sources like scientific experiment reports; see Wikipedia:Identifying reliable sources (science) for an overview of this.  Also, note that there is a No Original Research policy at Wikipedia.  --R. S. Shaw (talk) 18:21, 15 October 2021 (UTC)
@PhoenyxFeatherz:, have you checked out the Main links I mentioned?  These two: Electron transport chain and Oxidative phosphorylation seem like possible places for info about quantum tunneling in mitochondria.  The latter in fact has a passing mention about it. --R. S. Shaw (talk) 07:30, 20 October 2021 (UTC)
@R. S. Shaw:, yes, thank you so much. I also have located another article that might be better suited as well, such as: [Biology], specifically the enzymatic activity section. I believe these three (what you've cited and the one above) would be better suited for a more technical treatment. Thanks for your advice! PhoenyxFeatherz (talk) 21:14, 20 October 2021 (UTC)

This passage is badly dated: "Another human example is the sequencing of mitochondrial DNA from Neanderthal bones. The relatively large evolutionary distance between the mitochondrial DNA sequences of Neanderthals and living humans has been interpreted as evidence for the lack of interbreeding between Neanderthals and modern humans." The 1997 study cited has been superseded by multiple later genetic studies that actually confirmed interbreeding. This is also widely discussed on many other Wikipedia pages. As such, this should be updated. I'm a historian, not a biology or genetics expert, so I'll leave that to someone else. Just pointing out the problem. 
Ftjrwrites (talk) 02:33, 12 May 2022 (UTC)

Wandered over here after reading an article that talked about potentially thousands of copies of mitochondria DNA per mitochondria. Really? Then read here:

"One mitochondrion can contain two to ten copies of its DNA."
Really? First googled article contains quote:

"Studies on human samples have revealed that mtDNA copy number per cell can vary by several orders of magnitude, ranging from ~ 1 × 105 mtDNA copies in oocytes [35], ~ 4–6 × 103 in heart to 0.5–2 × 103 in lungs, liver and kidney [36]."
Since one of that quote's cites is from same era as the cite here, it is not new information, but perhaps our article's cite is just 'bad' with wildly small counts? Shenme (talk) 19:37, 6 August 2022 (UTC)

Without investigating thoroughly, it seems this may be a case of comparing apples to apple trees.  The article text references DNA copies per mitochondrion while the the quoted study mtDNA copies per cell.  Since an oocyte is commonly said to have 1 × 105 mitochondria, the numbers don't seem to be wildly off. --R. S. Shaw (talk) 23:52, 7 August 2022 (UTC)

I've counted at least five different locations where partial to total lack of function is discussed.  These should be consolidated into a single subheading, and probably don't merit more than a few words in the lead.  Honestly, all of Section 4 (Origin and evolution) & Section 5 (Mitochondrial genetics) are a mess and could probably do with a merging and rewriting.  
Please let me know if you're against this proposition. Darkskysunflowers (talk) 08:33, 18 September 2022 (UTC)

No adverse replies for two weeks so I'm going to edit for clarity.  Any disagreements please re-edit and/or let's talk it through. Darkskysunflowers (talk) 04:03, 2 October 2022 (UTC)
This page is seriously a mess.  It's gonna take me a week to edit even a few sections down. Darkskysunflowers (talk) 04:05, 2 October 2022 (UTC)
Hi @Darkskysunflowers: and a belated welcome! It seems you've discovered our dirty little secret: we're painfully short on editors interested in molecular biology. Many of our articles on the topic have been cobbled together without much thought for building a clear cohesive encyclopedia article. I'd hoped to cleanup this article a couple of years ago (see a few threads above) but other to-do list stuff took up all my time. If you'd like help with your cleanup task here, just let me know and feel free to direct me to particular sections you'd like me to work on. Otherwise, I'll cheer you on from the sidelines. Also if you have questions/concerns as you're working on the article, feel free to reach out to me here or at my talk page, or at Wikipedia talk:WikiProject Molecular Biology (where admittedly you won't find very many people either). Happy editing! Ajpolino (talk) 16:06, 6 October 2022 (UTC)
Hi @Ajpolino and thank you for the introduction/welcome!  I must confess I'm a much more prolific reader than editor; I tend to read papers cited in interesting wiki articles and sometimes find them misrepresented in the wiki page.  In the future, I'd like to edit more both for factual clarity and encyclopedic density / readability clarity.  Please - point me in any direction that may be mutually beneficial, especially as regards to community.  Otherwise I'll continue kind of stumbling upon glaring errors and fixing them as I go.  If I engage in any major re-working I hope you don't mind if I tag you to get feedback on them.  Thank you again! Darkskysunflowers (talk) 08:55, 11 October 2022 (UTC)
Of course, happy reading. If you ever find a larger project that compels you, feel free to start chopping away and I'll help out where I can. Nothing on Wikipedia can be irretrievably broken, so no need to fear. If I ever do find the time for a cell biology cleanup project, I'll ping you in case you're interested in joining. Cheers! Ajpolino (talk) 15:46, 11 October 2022 (UTC)

An editor has identified a potential problem with the redirect Maze bean and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 November 18#Maze bean until a consensus is reached, and readers of this page are welcome to contribute to the discussion.  MB 05:07, 18 November 2022 (UTC)

1) in subchapter "O2 and NADH" it is stated "electrons from NADH .. are transferred to O2 and Hydrogen": they are all ultimately transferred to O2 !! H2 is not produced, or what should this mean???
2) some subchapters are written in bad English (e.g., of the type "it turn" instead of "it turns".
3) in subchapter "additional functions" the phrasing suggests that ca. 600 proteins are encoded by mtDNA, while in facts it's only 13 (in humans) !!
4) in subchapter "human population genetic studies" it is stated that the splitting of humans and apes is 7884 years ago...this must be a joke!! WolfGreg9 (talk) 14:40, 16 July 2023 (UTC)

Mentioned but not explained.  What is their role?  cheers, Michael C. Price talk 01:32, 28 August 2023 (UTC)

To avoid expired info, editors might want to take a look at this review: doi:10.1016/j.cmet.2022.10.008. It talks about how mitochondria are not the powerhouse of the cell, but the regulators and signal transductors responsible for many more cellular processes. — Snoteleks (talk) 11:11, 4 December 2024 (UTC)