Talk:Chloroplast/Archive 1

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Archive 1

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I thought khloros was Greek for Green. (In the second paragraph:)

"The word chloroplast is derived from the Greek words photosynthasichlorium, which means green. . . ."

It seems to be too multisyllabic a word for something as simple as a color.

(Hope this works, it's my first attempt to join in.)

Mythomir (talk) 16:44, 30 June 2010 (UTC)

Well spotted, that was some vandalism added here a month ago! If you spot more again be bold and change it yourself. Thanks for pointing this out though. Smartse (talk) 20:44, 30 June 2010 (UTC)

I just created a page for plastids. The chloroplast is a type of plastid, and many of the comments about chloroplasts are true for all plastids, so I am tempted to change chloroplast to plastid in those situations.

Anyway, we need to consider how much we want chloroplast to repeat information found on plastid, and how much it should just contain facts unique to chloroplasts. Since the chloroplast is by far the most well known plastid, we might want to include a lot of the plastid information here. Any thoughts?

-adam

Josh Grosse asked if there are photosynthetic bacteria that don't use the Calvin cycle. Off the top of my head, yes. They use a reverse Citric acid cycle. This process was worked out by Evans, Buchanan and Arnon in 1966. "Chlorobium tepidum" and "Chlorobium thiosulfatophilum" use this cycle. I don't recall if they also use the Calvin cycle.

-adam

Lucky I just had photosynthesis in Biology, else I wouldn't understand a word of what that article says... ^_^. ugen64 21:14, Jan 4, 2004 (UTC)

I am correcting "...two lipid bilayer membranes, now thought to correspond to the outer and inner membranes of the ancestral cyanobacterium." to "...two lipid bilayer membranes, the inner of which is now thought to correspond to the plasma membrane of the ancestral cyanobacterium." Free-swimming cyanobacterium are single-membraned - the outer membrane of the chloroplast is contributed by the engulfing eukaryote.

-Peter

Free-living cyanobacteria have a second membrane, as is typical of Gram-negative bacteria. For a long while, it was believed the second membrane of chloroplasts came from the eukaryotic host, but evidence now points to it corresponding to the second cyanobacterial membrane. Thus, I've reverted this change. Josh 21:41, 20 Jul 2004 (UTC)
I'll defer to you if you're a biologist, but it is my understanding that the inner membrane of the cyanobacterium would correspond to the chloroplast's thylakoid membrane system and the outer membrane to the chloroplast's inner membrane.
-Peter

I'm not a biologist, but I've been reading a number of papers on the origins of eukaryotes, and this is what they say. I don't remember a specific reference; The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa by Cavalier-Smith surely mentions it, but I don't think it's available online. Thylakoids aren't something unique to chloroplasts, as the few cyanobacteria that lack phycobilins (e.g. Prochloron) have them as well. Josh 00:09, 22 Jul 2004 (UTC)

Can you please provide a quote attesting to the prokaryotic origin of the chloroplast's outer membrane? Cavalier-Smith's work sounds fascinating, and I'll endeavour to give it a read when I'm back at college, but in the meantime perhaps you can assuage my curiosity.
-Peter

I don't remember the particular references, but a quick web search gives results like:

Origin of a Chloroplast Protein Importer: These findings suggest that a component of the chloroplast protein import system, Toc75, was recruited from a preexisting channel-forming protein of the cyanobacterial outer membrane. Furthermore, the presence of a protein in the chloroplastic outer envelope homologous to a cyanobacterial protein provides support for the prokaryotic nature of this chloroplastic membrane.

Importance of the Plasma Membrane in the Cellular Origin and Evolution: That is, the outer membrane as the host's plasma membrane contains a large channel-forming protein (called porin), which is a constituent of the cell wall of prokaryotes, e.g., Gram-negative bacteria, and cannot be found in the plasma membrane...the outer membranes of these organelles are not the plasma membrane origin of the host cell.

Thanks for that. The abstract of the first paper seems compelling. The second paper is interesting, but the author's "recent evidence" is not cited, and the he seems to be in favor of a non-endosymbiotic model that contradicts Cavalier-Smith's own claims of a "Neomura" clade [1] linking the Eukaryota and the Achaea, which the cyanobacteria would fall outside of. Perhaps we should document competing theories of plastid evolution in separate write-ups and link them from here.
-Peter

I'd also like to refer you here [2] in defense of a eukaryotic origin for the plastid outer membrane. I really think Cavalier-Smith is kind of a lone gun on this hypothesis.

-Peter

request for more detail

I'd like to see the discussion of chloroplast DNA expanded a bit--a bit more detail on its origin, its similarity to (& differences from) prokaryotic DNA, how it differs from nuclear DNA, and how it has become increasingly significant in constructing molecular phylogenies. MrDarwin 02:26, 10 January 2006 (UTC)

it would be nice to talk more about the different kind of photosynthetic pigments. like Chlorophyll a, Chlorophyll b and carotene and the fact that they absorb different wavelengths of light to maximize the process of photosynthesis. user:arthur.etoo —Preceding undated comment added 19:38, 26 September 2016 (UTC)

A Useful Offline Source

One source that could be consulted if anyone here has access to it is this:

Green Plants : Their Origin and Diversity by Peter R. Bell and Alan. R. Helmsley, published by Cambridge University Press. Hardback edition : ISBN 0-521-64109-8 Paperback edition : ISBN 0-521-64673-1 . I recall that this work contains a great deal of information regarding the possible origins of the various membranes within the chloroplast, and includes electron micrographs and a range of other illustrative material that covers the structures of interest. For example, there is a diagram on page 4 which illustrates the distribution of important molecule complexes across the various thylakoid membranes - Photosystem I complexes are confined to the outer membranes of the grana and the stroma thylakoids, while Photosystem II complexes are absent from the stroma thylakoids. Page 6 contains a fairly detailed diagram of the membrane arrangement of a thylakoid in a higher plant. It also cites possible mechanisms for the creation of certain structures in the early evolutionary history of the cell (such gems among phrases as 'invagination of the plasmalemma' abound, so it is not light reading by any stretch of the imagination!). Hopefully this source will prove of use in dealing with the above discussion on the origin of various membraneous layers. Calilasseia 09:04, 10 January 2006 (UTC)

cytosol or cytoplasm

Is the stroma the equivalent of cytoplasm or cytosol? The article says cytoplasm, but according to professors, as well as the cytoplasm article, cytoplasm is cytosol plus the organelles. This article says that stroma is a fluid that contains DNA and ribosomes, so wouldn't that make it more like cytosol? I may be wrong, but I thought someone should look into that.

As the cytoplasm article states, the cytoplasm includes the cytosol and all the organelles. The chloroplast is an organelle, and as such is included in the cytoplasm. The cytosol is specifically all the fluid in the cell excepting that inside organelles. Rasuo (talk) 21:21, 1 November 2018 (UTC)

Protection Status

This article has been protected since October 2006. Is this still necessary? 75.17.192.215 08:16, 11 February 2007 (UTC)

I would like to add that everything found on this source is not 100% reliable, Thank you —Preceding unsigned comment added by 81.158.35.220 (talk)

This is quite likely, can you correct the content that you find to be in error? David D. (Talk) 20:11, 30 April 2007 (UTC)
The protection status seems a bit ridiculous! I'll take it off this time next week unless anyone objects in the mean time? Ptanham 17:40, 3 May 2007 (UTC)

Blocked status...illustration waiting...

I have draw a chloroplast showing its infrastructure, but I can neither add it nor make links to legends in the text because of its protected status...please, could you do anything for me by unlocking it....

Do Onions Have Chloroplasts?

Do onions have chloroplasts? —Preceding unsigned comment added by 203.78.9.149 (talk) 11:12, 8 March 2008 (UTC)

without a doubt. But not in all tissues of the onion. Plantsurfer (talk) 11:22, 8 March 2008 (UTC)

Inheritence and genetics

In humans (and other animals, I believe), mitochondria are inherited solely from the mother, and all mitochondria in an organism are identical (excepting chimera, of course). Do chloroplasts work that way? This line In certain plant species, such as tobacco, chloroplasts are not inherited from the male suggests not, for most plants. Does that mean that a plant cell has chloroplasts with different DNA? Nik42 (talk) 19:24, 10 May 2008 (UTC)

Chloroplast inheritance can be both uni (either maternal or paternal) and biparental, it will differ with the species of plant. See Hansen KA, Escobar LK, Gilbert LE, Jansen RK (2007) Paternal, maternal, and biparental inheritance of the chloroplast genome in Passiflora (Passifloraceae): implications for phylogenetic studies. Am. J. Botany; 94: 42-46. Silasmellor (talk) 21:15, 2 April 2010 (UTC)

Frequency of Vandalism

So, does anyone know why this page is subject to so much vandalism? I mean, it's not like it's an extremely popular or controversial topic, and yet looking through the history I see plenty of justification for it's current protection status. Obviously, no one has to answer this question if you don't know, but I was just curious as to if anyone had any theories. -Rundquist (talk) 17:13, 28 November 2008 (UTC)

Repetition

In the "Notes" section at the bottom of the page, #1 is repeated as #8.... i know, minor detail, but still... i'm OCD —Preceding unsigned comment added by Cafreen (talk • contribs) 17:54, 20 May 2009 (UTC)

Recommendation

You should have a section of functions of every cell organelle (part/s of a cell), not only for chloroplast. It should give an easy way of identifying its importance too. Encyclopedia's information should be organized as a Dewey Decimal System in the library so that more people can use it, and find information quickly. Just a comment, please. Not intending any personal rejection to Wikipedia's system whatsoever. -student_school09- 13:09, 12 August 2009 (UTC)

See Category:Organelles for a list of every organelle that we have an article on. Smartse (talk) 14:41, 12 August 2009 (UTC)

Image

The main image looks like it was drawn on MS paint. What is it doing up there? :/ 99.236.18.156 (talk) 04:43, 10 February 2010 (UTC)

If you mean File:Chloroplast_diagram.svg then it is a vectorised version of File:Chloroplast-new.jpg. Personally I think it is an improvement, it is only trying to show unfamiliar readers what different parts of the cpast are called. Feel free to improve it if you like. Smartse (talk) 09:57, 10 February 2010 (UTC)

Inaccuracy

I'm pretty sure chloroplasts produce glucose, not ATP

97.120.154.215 (talk) 21:20, 8 January 2011 (UTC)

Glucose is produced in the cytosol - triose sugars are exported from the cpast by the triose phosphate translocator and they are then joined to create a hexose. ATP is made by the chloroplast and is used to produce the triose sugars. This should probably be mentioned, but I haven't got a reference to hand at the moment. Thanks for posting though. SmartSE (talk) 22:00, 8 January 2011 (UTC)

When?

When did primary endosymbiosis occur? The article does not say. -- cheers, Michael C. Price talk 07:19, 3 May 2011 (UTC)

I think this is a point of contention, and not something that is easy to say definitely. Assuming that primary endosymbiosis and emergence of the Eukarya was coincident, which is also contested, i think based on fossil evidence the number 1.5 billion years ago. I don't have a reference at hand for that, but it should be easy to find one if need be. However, there is not wide agreement either that primary endosymbiosis occurred just once each for mitochondria and chloroplasts, and actually there is mounting evidence for multiple origins of chloroplasts. According to Lynn Margulis, endosymbiosis, not random mutation, is the driving force for speciation, which would imply an incredible number of primary endosymbioses... The whole discussion is somewhat speculative however, as hard facts are difficult to come by. Silasmellor (talk) 12:18, 11 May 2011 (UTC)

Edit request on 21 January 2012

{{edit semi-protected}} when talking about short-lived kleptoplastid in some dinoflagellates, that in heterotrophic (not only mixotrophic!) species should be added to where reference 10 is mentioned: Growth rate, pigments, and Rubisco analyses on heterotrophic dinoflagellate Pfiesteria piscicida have shown strong reliance of photosynthetic growth enhancement of the dinoflagellate on prey for plastid replenishment and rapid diminishing of the growth enhancement and degradation of pigments and Rubisco when the algal prey was depleted (Feinstein et al. 2002).

Feinstein, T. N. Traslavina, R., Sun, M.-Y., Lin, S. 2002. Effects of light on photosynthesis, grazing, and population dynamics of the heterotrophic dinoflagellate Pfiesteria piscicida (Dinophyceae). Journal of Phycology 38: 659-669.

Senjielin (talk) 13:25, 21 January 2012 (UTC)

Sorry, I don't understand; can you please say "THIS" should change to "THAT" and re-request; "Please change X" is not acceptable and will be rejected; the request must be of the form "please change X to Y - Thanks.  Chzz  ►  02:59, 28 January 2012 (UTC)
There seems to be some variation in the use of the terms heterotrophic and mixotrophic. For example, the reference used on the Kleptoplasty page talks about a species that is not fully heterotrophic. It seems okay to me that if they capture and use a chloroplast for a while, that they could be called mixotrophic. Sminthopsis84 (talk) 15:33, 5 February 2013 (UTC)

Chloroplast colour

"Many chloroplasts, but not all, are green because they contain the chlorophyll pigment." OK, if this statement is sustainable let's have some examples of non-green chloroplasts and citations. Plantsurfer (talk) 21:05, 26 October 2012 (UTC)

It's a vast topic that would need a lot of work. There is a photo of a diatom on the page, and a link to that group there. The algae were traditionally classified by their chloroplast pigments, yellow, yellow-green, brown, red. It is a big deficiency on this page, but it would require a lot of work to properly fix it. Sminthopsis84 (talk) 23:28, 26 October 2012 (UTC)
Maybe a little bit of work, but it would be worth it to explain why this happens, even if only briefly, in outline. As it stands, the sentence could be read as implying that some chloroplasts aren't green because they don't contain the chlorophyll pigment. At base level we only need to make clear the caveat that although all chloroplasts contain the green pigment chlorophyll, accessory pigments may be present that can change or override the green colour. Plantsurfer (talk) 19:00, 27 October 2012 (UTC)
That sounds fine to me, as long as it says chlorophyll a, i.e., the green one. Sminthopsis84 (talk) 19:19, 27 October 2012 (UTC)
This recent paper mentions red chloroplasts. SmartSE (talk) 23:40, 26 October 2012 (UTC)
Perhaps a section can be added that covers colour and shape of chloroplasts. I'll see if I can find my old class notes to use as a guide. Fortunately, some of the chlorophyll types have pages, e.g., Chlorophyll c1. There are reticulate shapes in Oedogonium (but a nagging memory suggests that similar shapes might exist in flowering plants), cup-shapes such as in Chlamydomonas, the half-cell-filling complex shapes of desmids (a picturesque example genus is Micrasterias) ... Sminthopsis84 (talk) 12:36, 27 October 2012 (UTC)
Yes a section on chloroplast shape, just enough to indicate the possibilities, would be good as well. Plantsurfer (talk) 19:00, 27 October 2012 (UTC)

Warning: spelling changes imminent

This page currently has quite a mixture of British and US spelling. To resolve the matter according to WP:ENGVAR, the first non-stub version of the page should be checked to establish a precedent. The very first version here is a solid treatment of the topic, and uses the US spelling "color" as its only (according to Microsoft Word's dictionaries) distinctive spelling variation, so I'm imposing that spelling on the page. Sminthopsis84 (talk) 17:57, 5 March 2013 (UTC)


chloroplasts are semi-autonomous

they're semi-autonomous organelles. the word "semi-autonomous" should be somewhere in the text, for example in section 2.3 (Chloroplast genome reduction and protein synthesis) or even in the introduction. Ryu (talk) 02:38, 5 May 2013 (UTC)

GA Review

GA toolbox
Reviewing
This review is transcluded from Talk:Chloroplast/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Chiswick Chap (talk · contribs) 13:02, 14 October 2013 (UTC)

I'll take this on. Chiswick Chap (talk) 13:02, 14 October 2013 (UTC)

GA Table

Rate Attribute Review Comment
1. Well-written:
1a. the prose is clear, concise, and understandable to an appropriately broad audience; spelling and grammar are correct. (Depends on required changes to the text)
1b. it complies with the Manual of Style guidelines for lead sections, layout, words to watch, fiction, and list incorporation. (Depends on required changes to the text)
2. Verifiable with no original research:
2a. it contains a list of all references (sources of information), presented in accordance with the layout style guideline. ok
2b. reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose). ok
2c. it contains no original research. ok
3. Broad in its coverage:
3a. it addresses the main aspects of the topic.
3b. it stays focused on the topic without going into unnecessary detail (see summary style). No, there's far too much detail, and it wanders. The topic is one that school pupils, both senior and junior, may look up, and the article is too complex for both those levels. The article is long enough for the problem to be resolved by splitting, leaving a generally comprehensible top-level article here, with a simple general overview (about its role in photosynthesis), and summary-style sections on the more advanced materials in main-linked sub-articles. As the article is now, it is simply going to overwhelm the general reader, let alone school pupils.
4. Neutral: it represents viewpoints fairly and without editorial bias, giving due weight to each. ok
5. Stable: it does not change significantly from day to day because of an ongoing edit war or content dispute.
6. Illustrated, if possible, by media such as images, video, or audio:
6a. media are tagged with their copyright statuses, and valid non-free use rationales are provided for non-free content.
6b. media are relevant to the topic, and have suitable captions. No, there are too many images, and a number are not relevant.
7. Overall assessment. Since there has been no progress for some days, and no sign of willingness by nom to make any of the suggested changes despite a clear way ahead having been proposed, must reluctantly fail this article this time around. Areas of improvement: focus and images.

Comments

Two immediate remarks - really beautiful images, though rather large at the moment; and the article is probably too long for comfort, so we likely need to create sub-articles and leave 'summary style' paragraphs behind. I'll consider the way ahead. Chiswick Chap (talk) 13:02, 14 October 2013 (UTC)

  • The images are unusually large for a Wikipedia article. I think I understand why this has been attempted, but it gives an unfamiliar look which is not really acceptable despite the elegant graphics work. The usual limit is 300px; perhaps the lead image could be 330px by exception but images further down should use the default thumb width.
  • Most of the pictures in the article are 300px, it's the important ones (like the chloroplast ultrastructure diagram or the chloroplast cycle ones) that are enlarged. Some of the >300px images are very wide landscape-type images where limiting them to 300px would make them far too small. Most of the algae photos are 300px or less.—Love, Kelvinsong talk 15:23, 14 October 2013 (UTC)
That is not acceptable. I hear what you say, but the overwhelming and definite impression is of far too many oversized images. Normal images need to be at DEFAULT size with no pixel specification at all. The article will not reach GA without substantial pruning and resizing.
  • The 'diversity of red algae' assemblage of images is quite beautiful -- and far too much detail, way off topic, for this article. It might be all right in rhodophyte. Please remove it.
  • The table of contents is too deep and too long: it's overwhelming and suggests daunting technicality even for those of us happy with Scientific American. It should be limited to 3 levels.
  • ((done}} Limited to two subheadings. The monster TOC was just to help me navigate the article and access certain "construction points".—Love, Kelvinsong talk 15:23, 14 October 2013 (UTC)
  • Short sections (like Kleptoplastidy) - merge or remove - that one could go into dinoflagellate. We're telling so much refined detail here that I'm losing the basic plot.
  • The core terms like chlorophyll and photosynthesis are clearly fine. More specialized terms like Plastoglobuli, Rubisco and Pyrenoids should probably not be section headings - some currently have very short sections and 'main article's, so a merge, and probably briefer text here, is clearly feasible. For example, the coverage of the hornwort Pyrenoids could be reduced to the first two sentences of the paragraph without great loss.
  • The article is not going to pass GA without these changes to the article's length. I have already indicated that the sequencing is less critical, but reiterating your position on the article's length is simply unhelpful. Chiswick Chap (talk) 04:30, 16 October 2013 (UTC)
  • For example, 'Pigments and chloroplast colours' is I think clearly a subtopic - this article is about the organelle, not about the pigments it may contain. The material should be made into a sub-article with a 'main article' link, leaving a single paragraph summarizing the typical (land plant) pigments. Readers who know what a Haptophyte is will then easily be able to navigate down for more detail.
  • Again, arguing in circles is no substitute for action. Chiswick Chap (talk) 04:30, 16 October 2013 (UTC)
  • Similarly, 'Protein targeting and import' is far too technical for a top-level article. The material should boldly be made into a sub-article with main link and one-paragraph summary here. Perhaps that's the 'Chloroplast DNA' split that's intended in the box? I think the circle image and one or two paragraphs should remain of the section; that may entail splitting off the whole section into a sub-article, rather than just the Protein targeting and import, but what is left should be brief and simple.
  • The sections on Endosymbiosis all need to be split off (probably as a single topic, Chloroplast endosymbiosis leaving a single, simple paragraph (it could almost just be the first paragraph of Primary endosymbiosis, actually) behind.
  • The cladogram is beautiful, ingenious, and should be about half as wide - you could I expect preserve the font size while bringing all the lines closer together.
  • I don't think its feasable to compress it to half its size, but I reduced it to 45% of the page width.—Love, Kelvinsong talk 15:23, 14 October 2013 (UTC)
It's a little better but now somewhat 'broken' in Firefox, and still very large by normal Wikipedia standards. Better compression by redrawing is needed.
That's strange—I designed the cladogram for firefox (though it works on other browsers too). I coded the cladogram for flexibility, so that it could compress or expand depending on the monitor width. But there's soft limit where lines start disappearing between the circles and text starts to collide. I don't think 45% width is bad at all (are "Wikipedia" graphics standards a bar to be reached or a floor to distance from?), and I don't think its a good idea to compress it further.—Love, Kelvinsong talk 23:31, 15 October 2013 (UTC)
  • On Firefox 24.0 the label 'Archaeplastida' is crossed by a green circle, while 'Apicomplexa' is cut by the edge of the image area. The pale gray label 'Ciliatea' offers very low contrast against a white background.
  • Informality - please replace "it's" with "it is".
  • Specialized chloroplasts in C4 plants - should be reduced to one brief paragraph. The elaborate image of C4 anatomy should be moved to a target such as C4 carbon fixation as it is only tangentially relevant here.
  • Location. 'Distribution in a plant' is a starter school topic, and should be near the top of the article.
  • Function and chemistry. The topic of photosynthesis is core to the article, and must be near the top of the article.
  • The more detailed chemistry (there are way too many subsections here) already substantially overlaps Photosynthesis which is rightly marked as a main article, so please replace everything in the Photosynthesis section with a single summary style paragraph with links to ATP, NADPH, Photophosphorylation, etc, and no subheadings.
  • Please stop arguing. This is your last chance to take action. Chiswick Chap (talk) 04:30, 16 October 2013 (UTC)
  • DNA replication is empty: either fill it briefly or remove.
  • See also - suggest we remove this altogether. If these need mentioning they should be linked in the text - stroma and thylakoid already are.
Done.

Article length and sequence

I agree that the photosynthesis section probably duplicates Photosynthesis a lot, but I think it deserves plenty of weight in the chloroplast article, given how closely chloroplasts and photosynthesis are related. Notice I didn't really talk about the excitation/ionization of the chlorophyll molecule and other off-topic stuff, I mainly stuck to stroma molecules, proton flow across the thylakoid membranes, and thylakoid proteins. Some of the stuff like pH and the locations of various stages of photosynthesis are more closely related to Chloroplast than Photosynthesis. Either way, splitting this part off into Photosynthesis and figureing out which parts are already there and which aren't is going to be a daunting task, especially given the sorry state of the Photosynthesis article...

About the other sections, I do not think the Endosymbiosis, Structure, or Development sections should be cut. They are integrally related to the topic of the chloroplast, even the Development one which I tried to keep about chloroplasts as opposed to chromoplasts or amyloplasts. Chloroplast DNA is probably getting too big for the rest of the article, and I agree that the second part of it reeks of PROTEINDUMP. However there really isn't an existing Chloroplast DNA article to merge it into, and any article made from this section would probably go too off topic into protein import (which is fine in the larger scope of the Chloroplast).

The request was and is to split off a new Chloroplast DNA article, leaving a 'main' link and a short, simple, crisp, richly linked 'summary style' section (with the key refs only) behind. There might indeed be a separate article on Chloroplast protein import, or whatever, again leaving a summary behind.

Also there is a reason for the article's current sequence. I think it's most logical to start with the organelle's endosymbiotic history and its evolution, then into its genetics, and then its physical structure. Then it goes out into its cellular location, and then its organismal location. Then we have the Function section, and its development and reproduction section. So the article goes:

  1. Where it came from (and what organisms have a chloroplast)
  2. What happened to its genes as it evolved
  3. What these genes build (the physical structure)
  4. There the chloroplast itself lies
  5. What the chloroplast does (possibly can be switched with the structure and location sections)
  6. How it develops and reproduces itself

—Love, Kelvinsong talk 16:05, 14 October 2013 (UTC)

OK, I hear this, whatever my personal preference. Your words here are far clearer and simpler than anything in the article ... you know what is coming here ... so why not take these simple clear phrases and make the article as comprehensible as they are? You are familiar I believe with Mitochondrion, a GA -- it has A FEW of your fine images, it's half as long as Chloroplast currently is, it starts pretty simply with history, and it has several summary style sections like Inner mitochondrial membrane, Cristae, Mitochondrial matrix, each with a Main article, and guess what, there's even a sub-article called Mitochondrial DNA. If you make this article like that, it'll be a GA in no time. It won't be very difficult, I think, just some splitting and summarizing. Chiswick Chap (talk) 17:10, 14 October 2013 (UTC)
  • I see you are trying to insist on the lead image, but it is frankly much too complex as an introduction to a top-level subject, and it seems it is setting the wrong tone for the rest of the article - you are attempting to push through something far more complex and far more heavily illustrated than Mitochondrion, when that article is quite complex enough, and has quite enough images. Some prompt movement on this front is now necessary to avoid a quick fail. Chiswick Chap (talk) 17:26, 14 October 2013 (UTC)

Image size

I see that you've been removing all the specified image widths from the article. While this isn't much of a problem in some of the sections (like Structure), it's messing things up in the Endosymbiotic history section. Ironically your width removing has made some of the algae pictures bigger than they need to be (the cryptophyte-derived dinophyte one looks particularly funny). Please put the image widths back in that section. Also, I'd kindly ask that you don't touch the non-photographic pictures—for one, they look much worse with the thumbnail frames, and two, most of them (like the lead cartoon, and the thylakoid diagram, but not the Rubisco picture actually) are specially designed for the width they are displayed in the article—any other width makes the text very blurry. Ahh, the myth of the scalable SVG…—Love, Kelvinsong talk 17:50, 14 October 2013 (UTC)

The photographs should not become bigger, and I intentionally left the non-photos for now except the Rubisco which seems to be fine smaller - I suspect some will move into sub-articles and the rest we can think about. It isn't really acceptable to have so many such large images, it must be possible to thumbnail them somehow - at worst, there can be buttons 'click for image', after all. I'll tweak the dino. Chiswick Chap (talk) 18:52, 14 October 2013 (UTC)

Lead image

While I disagree that the lead cartoon is complex at all (other than making distinctions between the different types of thylakoids, it's actually quite basic in its labeling), I think its important for it to be included in the lead, and at a size where the text is readable—(the lower limit is 8 pt, which corresponds to a diagram width of 400 px). What would be acceptable for you in terms of size and content? Fewer (or no) labels? Removing the thylakoid stack at the bottom?—Love, Kelvinsong talk 23:22, 15 October 2013 (UTC)

The problem with the images is many-fold. They are too large, as stated, likely causing problems on portable devices; they are too complex, which is making them actually unencyclopedic, if by that we mean suitable for a general Wikipedia audience; they are too numerous, crowding the text. The 'lead cartoon' is already above the general level, and is certainly not suitable as the way in to a top-level article, though it might possibly be usable further down after a general overview and then an introduction to the less familiar terms. You will see that some of the other images, even larger and more complex, are in these terms still less suitable for an article, while the mass of images of algae seems entirely out of scope. Chiswick Chap (talk) 03:40, 19 October 2013 (UTC)

Paulinella

Not sure why you characterize Paulinella as a "weak" exception. Is it the only known example of a recent endosymbiotic event. If so, it would be better to say that, and leave out the word "weak", which sounds like an editorial value judgement. Plantsurfer (talk) 16:43, 3 November 2013 (UTC)

It's because me and User:Sminthopsis84 decided a while ago that the chromatophore in Paulinella shouldn't be talked about as if it were a "real" chloroplast.—Love, Kelvinsong talk 18:03, 3 November 2013 (UTC)
Well I wouldn't disagree with you and User:Sminthopsis84 on that, but the use of the word "weak" in that way conveys no information, says nothing about why, and leaves the reader wondering and guessing. Of course, now that the link to Paulinella is there, the reader can see a little more explanation, but the Paulinella article does not properly enlarge on the point you made above. I suggest that this is of sufficient interest and importance that you consider using up just a few extra words to explain. Or, if you wish, I can have a go at it. Plantsurfer (talk) 18:21, 3 November 2013 (UTC)
I don't know how to say it in a nonawkward way, so feel free to take a whack at it—Love, Kelvinsong talk 18:38, 3 November 2013 (UTC)
Good discussion. I think that just removing the word "weak" is a good choice, and have implemented that. "With one exception..., all chloroplasts can probably be traced ... The chloroplast of Paulinella wouldn't belong in some discussions of the ancestry of chloroplasts, but I think it is fine to refer to it as a chloroplast in this context. Sminthopsis84 (talk) 18:54, 3 November 2013 (UTC)
Perfect! Plantsurfer (talk) 19:30, 3 November 2013 (UTC)

RuBisCO Capitalization change?

Most of the article refers to the protein as rubisco instead of RuBisCO. Should the capitalization be changed? Jeff (talk) 06:05, 26 February 2016 (UTC)

Chloroplast structure review

There were sections that were to technical and went over my head and especially would have went over my head as an intro biology student. One of these especially was the section about Plastoglobuli. This section never really defined what plastoglobuli are but instead went into more technical and science specific terms related to plastoglobuli. Another section that I thought has this issue was the "pigements and chloroplast colors" section. This section further broke down into subheadings such as chlorophylls and carotenoids. These sections were so specific that I think it was hard to stay away from the really technical terms to describe what these pigments are in a chloroplast.

Another issue I found was that some of the papers that were cited as being used as sources online were really only previews of papers and I couldn't actually read the entire paper without signing up for a membership or paying a fee. This would make it difficult if I wanted to do further research into the topic as a college student looking to this article for reliable sources.

I think chloroplast structure is so detailed and that this sub section within the article possibly glazes over some of the details that are important for understanding as a student. This could be avoided by making this section its own article and going into further, more thorough detail. — Preceding unsigned comment added by Emily2930 (talk • contribs) 02:51, 28 September 2016 (UTC)

Location section review

This first paragraph doesn’t really tell me about the distribution of chloroplast in a plant, as much as it describes which plants contain chloroplast. It does introduce the idea of where chloroplast can be found (collenchyma tissue), but the clorenchyma cell information does not seem relevant to the heading of this section The second paragraph does help me understand and get a clear picture of the actual distribution of the organelle within specific plants. I found this third paragraph very helpful in understanding how environmental conditions affect the organelle’s location in the cell, and what the plant does to minimize damage.This last paragraph on chloroplast movement was also detailed enough to understand the basics of the plant’s cellular defenses against environmental conditions.Overall, this section on location encompasses the major components of chloroplast distribution in the plant cell and how environmental or outside forces cause defense responses at a cellular level. — Preceding unsigned comment added by Analuciarg (talk • contribs) 20:42, 28 September 2016 (UTC)

Chloroplast Review

-Is the article well organized? 

   The article has decent organization, and groups information into subheadings. I think the history should be taken out of the introductory paragraph because that information should be under the subheading title "Discovery". The "Discovery" section is very short in comparison to other sections. The introduction, while it gives great information, is rather lengthy for an article that is divided into subheadings about specific topics concerning the chloroplasts. I think if some of the information presented in the introduction was relocated to a subheading that better fit the information, it would help the article flow more. The introduction could be narrowed down to a brief overview, with the information presented in each subheading being the main part of the article. If these changes are made, the introduction will briefly introduce the topic, and each subsequent subheading will give the student increased knowledge on chloroplasts. This type of organization is preferred by students who are trying to learn about something that they have little or no previous knowledge of because they can become slowly introduced to the topic through each section.

-Is the article easy to understand? 

    For me, as a chemistry major, the article is not too difficult to understand. However, I think if some of the science jargon was taken out of this article, it would be more beneficial for all students. While it is helpful to teach people the science jargon as the article progresses, I think it is also helpful to decrease the level at which this article is written. For example the sentence in the introduction that reads "Chloroplasts' main role is to conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water," has a lot of different ideas and topics being introduce without thoroughly explaining each one. This sentence could be simplified and broken into a couple of different sentences. Taking the first part of the sentence, you could change it to "The main role of the chloroplast is photosynthesis. This occurs when chlorophyll, the photosynthetic pigment in plants, captures sunlight and converts it to usable energy." From these two sentences, then you can further explain the molecules and about freeing oxygen from water. I think it is important to start at the most basic level and then build your way up so you make sure the reader follows every step of the way.

Mk23millerMk23miller (talk) 01:05, 29 September 2016 (UTC)

test — Preceding unsigned comment added by Akastigar1 (talk • contribs) 21:11, 29 September 2016 (UTC)

Review: DNA Replication

The Leading Model of cpDNA Synthesis This beginning introductory section seems fine in terms of content and citation. It is easy enough to understand the replication protocol for chloroplasts, however, I do think that the supporting figure is what really aids individuals that are not scientists and/or studying science. That being said, the figure depicting chloroplast DNA replication is severely lacking. You barely see the theta intermediary, which should be included and identifiable if it is discussed in the corresponding section. Likewise, the lack of differentiation between the single-stranded DNA and double stranded DNA is not very clear. It's purpose within this section is very worthwhile, since this is starting to get into the deeper science, but a better figure should be found or created to better and more accurately represent the processes that are occurring.

Deamination There are a lot of obvious grammatical issues in this section. It simply doesn't flow well and should be revised. Likewise, there should be a link to homologous recombination. For the most part, the rest of the section is in simple English and easy to understand, but without some supporting information about what homologous recombination is or a link to its own page on Wikipedia, then it's just jargon thrown in the middle of the paragraph that does not make sense. However, the supporting figure for this section is wonderful, and further highlights what I mentioned before about the need for readable supporting figures. I know nothing about deamination, but the figure was wonderful for helping understand the process that wasn't as wonderfully translated through the text.

Alternative Model of Replication The first sentence has a missing "the" after "One of...," however this starting sentence is incredibly strong. The link to homologous recombination is present, which was lacking in the last section. Second sentence, it should probably be edited so that instead of just saying "complex structures" there is, once again, direct reflection back to DNA and to exactly what part or conformation of DNA they are referencing. I assume the OP meant to say "complex chromosomal structures," but, once again, someone random stumbling upon this page with little to no science experience might not make that connection. Other than that, there should be a hyperlink to another page referencing or defining plastomes.

Gene Content and Protein Synthesis Solid section, with lots of outside references, internal references to other sections on Wikipedia, and the like.

Chloroplast Genome Reduction and Gene Transfer Same as above, this section is really interesting and well written. It is quite jargon-filled, but I think since there are links to their pages accompanied, that understanding what is going on wouldn't be a significant problem.

Protein Targeting and Import A figure will be needed for this section if it is to remain. It is incredibly important to talk about the position of proteins about the cellular matrix of both the cell, and most specifically, around the chloroplast, but it currently is not very accessible to the normal person and a supporting figure would help significantly. As of right now, it's a load of jargon that goes over my head, and either needs to be explained out or have some support to make it more understandable.

Transport Proteins and membrane translocons Again, the following section sets a wonderful precedent for the one prior. The way the first paragraph is written is how lingo and scientific information should be written if the writer wants to keep it true to form. They make the connection blatantly that the folding of the protein immaturely would cause the chloroplast proteins to start functioning outside of the chloroplast. That connection alone will really help people who don't know much about these internal cellular processes understand what is going on. The same thing needs to be done in the section above with protein targeting.

Akastigar1 (talk) 21:42, 29 September 2016 (UTC)akastigar1

Chloroplast Review

Is the article easy to understand? 

    As a biology major, the article was fairily easy to understand for me.  As for students that were just starting out with biology, it may be somewhat difficult for them to understand.  Some of the terminology may be a little too technical for them to understand.  Many of the sections were very specific and used several scientific terms that students in intro biology class may not understand yet.  One section that stands out is the one about Plastoglobuli.  The section doesn't really define what plastoglobuli is and went into more scientific terms to describe plastoglobuli.  Overall the article can be understood with at least a little bit of knowledge of biology.


Is the article well organized? 

     The article is decently organized with information grouped into separate sections.  The introduction is a bit lengthy and has some unnecessary information in it.  The information about the history of chloroplasts should be included in the "Discovery" subheading instead of in the introduction.  Some of the information in the introduction would fit better in other sections.  If some topics were relocated to better sections, I think the article would flow better.  Overall, the article is organized fairily well and the subheadings make it easy to find the information you are looking for.

Aruland25Aruland25 (talk) 01:02, 1 October 2016 (UTC)

Guard Cell Chloroplast and Reference Sections

Hi, I'm a Cell Biology student. I have read through the Guard Cell Chloroplast Section of this article and I have a couple suggestions. The missing controversial chloroplast functions. Also, different plant species can have a different number of chloroplasts in their guard cells.[1] In the References section of the Chloroplast article, I noticed that references 123 and 128 are the same reference.--Patterson115 (talk) 18:24, 1 October 2016 (UTC)

  1. ^ Lawson T. and J. I. L. Morison. Essay 10.1 Guard Cell Photosynthesis. Plant Physiology and Development, Sixth Edition.

Iridoplasts?

I had a look at this CSM article. I can't find anything on here about iridoplasts. Is that a fringe or new term? Just wondered if something needs added, although I don't know enough about the subject to know where it belongs (if at all) Autumn Wind (talk) 19:32, 26 October 2016 (UTC)

Wrong image placement

There's an image that's improperly formatted over the section on regulation. I attempted to fix it but couldn't get the formatting right.FamAD123 (talk) 19:10, 28 November 2016 (UTC)

C-Class Article?

Get real! This is one of the best written, clearest and well presented Wikipedia artiucles I have come across! Well done to all editors. Stub Mandrel (talk) 18:56, 11 May 2017 (UTC)

External links modified

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Lipid biosynthesis

I have written a bit of text for lipid synthesis - to be included under "other chemical products"

Fatty acid synthesis in plants occurs in the plastid [1]. The carbon used to form the majority of the lipid is from acetyl-CoA, which is the decarboxylation product of pyruvate [1]. Pyruvate may enter the plastid from the cytosol by passive diffusion through the membrane after production in glycolysis [4]. Pyruvate is also made in the plastid from phosphoenolpyruvate, a metabolite made in the cytosol from pyruvate or PGA [1]. Acetate in the cytosol is unavailable for lipid biosynthesis in the plastid [2]. The typical length of fatty acids produced in the plastid are 16 or 18 carbons, with 0-3 cis double bonds [3].

The biosynthesis of fatty acids from acetyl-CoA primarily requires two enzymes. Acetyl-CoA carboxylase creates malonyl-CoA, used in both the first step and the extension steps of synthesis. Fatty acid synthase (FAS) is a large complex of enzymes and cofactors including acyl carrier protein (ACP) which holds the acyl chain as it is synthesized. The initiation of synthesis begins with the condensation of malonyl-ACP with acetyl-CoA to produce ketobutyryl-ACP. 2 reductions involving the use of NADPH and one dehydration creates butyryl-ACP. Extension of the fatty acid comes from repeated cycles of malonyl-ACP condensation, reduction, and dehydration. [1]

Other lipids are derived from the methyl-erithrytol phosphate (MEP) pathway and consist of gibberelins, sterols, abscisic acid, phytol, and innumerable secondary metabolites. [1]

sources: [1] Buchanan BB, Gruissem W, Jones RL (Eds.). 2015. Biochemistry & Molecular Biology of Plants (2 ed.). Wiley Blackwell. pp 344-352.

[2] Bao X, Focke M, Pollard M, Ohlrogge J. 2000. Understanding in vivo carbon precursor supply for fatty acid synthesis in leaf tissue. Plant Journal 22, 39–50.

[3] Ohlrogge J, Browse J. 1995. Lipid Biosynthesis. The Plant Cell 7, 957–970.

[4] Proudlove MO, Thurman DA. 1981. The uptake of 2‐oxoglutarate and pyruvate by isolated pea chloroplasts. New Phytologist 88, 255–264.

Rasuo (talk) 15:52, 8 November 2018 (UTC)

After a few days I got autoconfirmed so I just made the edit myself... Rasuo (talk) 18:46, 15 November 2018 (UTC)
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