Talk:Chloroplast

Chloroplast was nominated as a Natural sciences good article, but it did not meet the good article criteria at the time (October 19, 2013). There are suggestions on the review page for improving the article. If you can improve it, please do; it may then be renominated.

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To-do list for Chloroplast: Function list Iron metabolism Lipid synthesis Review Evolutionary Origin and Chloroplast DNA sections for technicality Evolutionary origin Add image showing types of primary and secondary endosymbiosis  Done Chloroplast DNA Describe protein synthesis in a chloroplast— is a good source Expand Genome reduction section—Genome size differences between algæ and land plants, chloroplast stuff coded by the nucleus Expand Genome reduction section or start new section—relationship between nucleus and chloroplast, ie protein transport, chemical signaling Chloroplast ploidy and relation to size Chloroplast DNA replication Protein import Structure Organize Structure section—add sections and Main article links  Done Possibly remove chloroplast ultrastructure image and box? Reason for, evolution of, and function of pyrenoids Mention corresponding cyanobacterial parts Chloroplast colors—types of pigments, functions, and effects (Absence of green absorber makes chloroplasts, and their leaves, green)  Done Movement Cytoplasmic streaming * Movement during infection Chemistry Add overview—what goes "into" a chloroplast and what comes out? Expand—Embedded proteins, locations, protons being on the inside of the thylakoids Expand—NADP+/NADPH—it's mentioned in the lead, and nowhere else  Done Expand—Calvin cycle—mention Rubisco, NADPH recycling  Done Find citations of pHs  Done Transplastomic plants Remove jargon Other Location in a plant *Add info on plastid family  Done *Possible interconversions *Algæ with chloroplasts destroyed cannot regenerate them *Apicoplasts  Done Add info on chloroplast replication/division  Done —Good sources— [1] [2] [3] [4] [5] Chloroplast division vs plant cell division synchronization Chloroplasts in C4 plants  Done Image that needs a home—File:Chloroplast division.svg Images that need homes—File:Plastids types en.svg, File:Plastids conversions-en.svg Done

This article is written in American English, which has its own spelling conventions (color, defense, traveled) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.

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Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Emily2930, Akastigar1, Arthur.etoo, Mk23miller. Peer reviewers: Analuciarg, Aruland25.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 17:34, 16 January 2022 (UTC)

Mention why chloroplast not in animal cell

It should be mentioned in the article why chloroplast is not found in animal cell. — Preceding unsigned comment added by ScienceKeeda (talk • contribs) 15:32, 30 September 2020 (UTC)

A wrong redirect

one of the hyperlinks says Chlorophyll c but it ridirect to Chlorophyll b despite Chlorophyll c page does exist. comment added by User:(S.A.)(S.F.)BUGOC — Preceding undated comment added 21:19, 9 April 2021 (UTC)

Subtractive pigments won't give purple

The article says:

Rhodoplasts have chlorophyll a and phycobilins for photosynthetic pigments; the phycobilin phycoerythrin is responsible for giving many red algae their distinctive red color. However, since they also contain the blue-green chlorophyll a and other pigments, many are reddish to purple from the combination.

There's a reference (which I can't access), but it doesn't make sense. Phycoerythrin is supposedly red, although the absorption spectrum in our article on it shows that it doesn't absorb much blue, so it's apparently purple already. Chlorophyll is green, which means it absorbs red and blue. So if you have both, then red, green, and blue will all be absorbed to some extent. In other words, adding chlorophyll doesn't make it more purple, it makes it less purple! It absorbs the blue and red of which purple is composed. We're talking about subtractive colors, not additive. If we were shining colored lights, then yes, shining a red light and a blue-green light on the same spot might give a purple. I think the purple color of some "red" algae is simply due to the phycoerythrin, plus maybe some other pigments. Eric Kvaalen (talk) 18:36, 28 January 2022 (UTC)

Unreadable

Some diagrams on this page esp. the evolutionary tree are completely unreadable/unviewable on mobile and ipad. Mindyobusiness12 (talk) 08:06, 30 December 2022 (UTC)

The table under "Pigments and chloroplast colors" could be improved for dark-mode users.

I noticed that the table under the "Pigments and chloroplast colors" has some design errors that show under dark-mode. This would be a simple edit of the table to rectify. Happy to do it if granted the ability.

Unfortunately I cannot attach a screenshot of the table from my PC due to copyright issues.

FropFrop (talk) 06:34, 14 June 2023 (UTC)

Relation between thylakoid membranes and cristal membranes of mitochondria.

The article states that there is no relation between the chloroplast and mitochndrial inner membranes- but maybe between thylakoids and mito inner membrane. Considering the ox-phos proteins of the mitochondrion are mainly located in invaginations of the inner membrane (cristae), the homology becomes much clearer:
In terms of proteins, the thylakoid membranes are homologous to the mitochondrial inner membrane, and in particular to the cristae membranes where respiratory and phosphorylative complexes are concentrated. There is no question that the cF1Fo ATP synthase is related to the mitochondrial ATP synthase, or that b6f is related to bc1 (complex III). Furthermore the direction of pumping is the same in both- electron transfer complexes pump from the side where the DNA is (mito matrix or cplast stroma) to the other side. The only topological difference is that the cristal invaginations are still open to the intermembrane space,thus in protonic contact with the cytoplasm, so rather than going acid the mitochondrial matrix becomes alkaline. If the cristal invaginations were pinched off from the inner membrane and free-floating inside the mitochondrion they would be topologically equivalent to thylakoids. I'm sure someone must have pointed this out, but I don't have a reference and I understand we can't publish original research/ideas. Eaberry (talk) 18:26, 4 September 2024 (UTC)

I think this is a great point. It's also how I was taught to think about mitochondria vs chloroplast proton transport in advanced biochem. I might be able to dig through my textbook to see if it's discussed in there.

I'm starting to take on reworking this article (see my Talk post detailing proposed changes). If you'd be interested in helping out reworking the membrane section, I'd welcome the input! Though much of the membranes info will probably be moved to the main article Chloroplast membrane. Cyanochic (talk) 18:03, 10 October 2024 (UTC)

Structural rearrangements to article (Evolution and chloroplast lineages)

I fell in a rabbit hole making some edits to this page today and then found the comments from the review for good article status in 2013. I wanted to more verbosely clarify what I changed and why in case someone would rather revert and discuss. Changes made in my recent edit were primarily of the content about evolution of chloroplasts and different lineages of chloroplasts. I didn't remove much written content unless it was redundant with other parts of the article.

Additionally, if the momentum is there, I think this article could be brought to GA status with a little time (and article splitting, which was discussed a lot from the GA review also.) Following the posting of this, I'll pull together my suggestions for improving the article for discussion and share on relevant WikiProjects to see if there's more interest.

Explanation of major structural changes:

I made the section "Endosymbiotic origin of chloroplasts", "Primary chloroplast lineages", and "Secondary and tertiary chloroplast lineages" to group those ideas in place of the previous layout. The previous layout placed all of these under one heading "Lineages and Evolution" that then went back and forth in subheadings between primary endosymbiosis then describing primary chloroplast groups, then going into evolution of secondary and tertiary chloroplasts, and then detailing those groups. I did not change content nearly at all in both chloroplast lineage sections (beyond adding "see also"s linking to main pages for those groups).

I did reorganize information within "Endosymbiotic origin of chloroplasts" pretty heavily. The redundant information became more apparent as I grouped like ideas together. This led to the majority of shrinkage of the overall article. I don't believe I removed any significant information that wasn't redundant, but I organized it for what made sense for the flow of information (to me). I did reduce the explanation of what cyanobacteria are pretty heavily, since it was already directed to its own page. I did move about a paragraph of information originally in the endosymbiotic origin of chloroplasts to more topical sections, primarily to structure for a chunk on membrane structure, and a section on genes in chloroplasts to the Chloroplast DNA section. Cyanochic (talk) 03:26, 7 October 2024 (UTC)

Proposed major changes to Chloroplast article (to reach good article status??)

As explained in my recent talk page post, I am in a deep rabbit hole thinking about how to improve this page and I want to get all my proposed ideas out while the motivation lasts. Some of this is my own independent conclusions and some of this is based off of some of the info from the review for good article status in 2013. (As the work week is just starting, I probably won't be jumping after any of these for a few days.)

Thanks for reading and I look forward to hearing everyone's input!

Proposed changes for improvement:

1. Shorten the section Chloroplast DNA (maybe a paragraph or two) to a much smaller section pointing to the main article Chloroplast DNA. The separate article was originally created as a split from this page. The information here is likely mostly/all redundant (I have not thoroughly checked). Once checked, this would be a pretty rapid change to make. I'm not set on where this falls in the broader structure though.
2. Shorten (by a lot) subsections that have their own main pages.
   1. Chloroplast membrane sections within Structure. Main article:Chloroplast membrane doesn't appear to originally be split from the Chloroplast article. Would probably involve moving information over from this article.
   2. Many Structure subsections specifically have their own articles (e.g. Thylakoids) and could be shortened. See detail in overall proposed structure below.
   3. Many Function and chemistry subsections have their own pages (e.g. Guard cells and Photosynthesis plus reactions therein) Possibly restrict to just "Function"?
3. Reorder sections for a more linear flow of information. I think it makes sense to have "Structure" and "Function" next to each other and "Location" and "Differentiation, replication, and inheritance". This wouldn't be much work, but would potentially improve the overview of the topic to a new learner a lot.
4. Highlight primary pigments section more and point to Photosynthetic pigments as main article. A small aside, photosynthetic pigments could definitely use some expansion. Maybe move info from this article over there.

Less developed ideas that need more work

These two are sections that I consider more "out of my wheelhouse" (scientifically/academically speaking) and while I'd be willing to tackle them, someone else with more expertise might be faster and have on hand knowledge about what's important enough to keep or not

1. Shorten chloroplast lineage sections. This would require a larger amount of work to look at what exists in lineage main articles and a decision on what is important for a chloroplast article versus what is fine to leave out in favor of pointing to the main articles.
2. Shorten and overall improve the flow of information in Differentiation, replication, and inheritance. Admittedly a little too "cell biology" for my expertise. Also seems very plant focused, but I'm trying to focus on working with what's already there.

Overall proposed structure of main headings:

I included level 1 sub-headings only where I propose major restructuring/content changes, others would remain as is.

• Lead/summary section - finished for now Cyanochic (talk) 00:39, 21 October 2024 (UTC)
• Discovery and etymology - finished for now Cyanochic (talk) 00:39, 21 October 2024 (UTC)
• Endosymbiotic origin of chloroplasts - finished for now Cyanochic (talk) 00:39, 21 October 2024 (UTC)
• Primary chloroplast lineages - finished for now Cyanochic (talk) 00:39, 21 October 2024 (UTC)
• Secondary and tertiary chloroplast lineages
• Chloroplast DNA
• Structure
  • Membranes
  • Stroma
  • Pyrenoids
  • Thylakoids
  • Pigments
  • Specialized chloroplasts in C4 plants
• Function
• Location in cells
• Differentiation, replication, and inheritance (could use a pithier heading)
  • Differentiation
  • Replication
  • Inheritance

Cyanochic (talk) 04:30, 7 October 2024 (UTC)

The thrust and overall structure of the proposed rewrite sound like a very good idea to me! Felix QW (talk) 10:01, 7 October 2024 (UTC)

Updated the lede today, mostly took out unneccesary detail/scientific jargon and put into 3 paragraphs that I think flow much easier. I might do more tonight, but I'll work on some of the larger content changes over the weekend. Cyanochic (talk) 03:12, 12 October 2024 (UTC)

I fully support the proposed reorganization and removal of clutter, but I would advocate for making an effort to retain the visual material created by User:Kelvin13. It beautifully illustrates and adds to the text. TheBartgry (talk) 09:26, 21 October 2024 (UTC)

I agree! I think I've removed one image (diagram of a nucleomorph) but otherwise I have only moved images around. Cyanochic (talk) 14:21, 21 October 2024 (UTC)

Thank you very much for your work! As an aside regarding the images, at least for me on desktop the cladogram and the images in "Endosymbiotic origin of chloroplasts" really squeeze the text. It could work to move the cladogram to the right, but the template that generates it does not seem to allow for that. Is there a good reason not to include this as a vector image instead? Felix QW (talk) 09:44, 21 October 2024 (UTC)

In case it is of use, I uploaded an autotraced SVG to Commons under File:Chloroplast Cladogram.svg. Felix QW (talk) 10:27, 21 October 2024 (UTC)

This is actually exactly what I needed! I was struggling with the same issue while editing that section and the old GA review also had a conversation about it. I couldn't make the image smaller without words wrapping onto 2 lines. I'll update this later today! Cyanochic (talk) 14:24, 21 October 2024 (UTC)

I have updated this to the SVG version of the cladogram. I centered it to be its own area of text as it's fairly large, but contains a lot of useful and summarizing info for the section. I would love your thoughts on that versus having it to the right under secondary endosymbiosis figure.

In a related issue, the Chloroplast DNA SVG is really great as it is interactive, but it has an issue with the caption overlapping the bottom of the image. Do you know of a way to fix this or would it be an adjustment to the template? If so, I already plan to post on the template talk page for capitalization requests (dna to DNA and nicotiana to Nicotiana) also and can ask there at the same time. Cyanochic (talk) 16:42, 21 October 2024 (UTC)

I had a look at that template just now. It is based on File:Chloroplast DNA blank.svg, so any capitalisation changes would need to be done there. I'll see what I can do, but I find that svg file somewhat confusing. For what it's worth, the capitalisation on File:CtDNA.svg is easy to fix in a text editor. Felix QW (talk) 17:32, 21 October 2024 (UTC)

I did manage to "fix" the caption in the template, but I find the whole "diagram as Wikitext" concept to be rather fragile. Felix QW (talk) 17:37, 21 October 2024 (UTC)

I uploaded a new version of the base SVG, fixing the capitalisation and making the text much more easily editable in the future. I also changed the fonts slightly and reduced the size of "Chloroplast DNA" a little, so that the image would be a little less crowded. Felix QW (talk) 19:08, 21 October 2024 (UTC)