Wiki Education Foundation-supported course assignment

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  This article was the subject of a Wiki Education Foundation-supported course assignment, between 29 March 2021 and 15 June 2021. Further details are available on the course page. Student editor(s): Ttbuii.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:26, 17 January 2022 (UTC)Reply

Wiki Education Foundation-supported course assignment

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  This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 16:29, 16 January 2022 (UTC)Reply

C4 article has better intro.

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The intro at C4 tells me that there are three mechanisms which to me is a better intro.

C4 carbon fixation is one of three biochemical mechanisms, along with C3 and CAM photosynthesis, functioning in land plants to "fix" carbon dioxide (binding the gaseous molecules to dissolved compounds inside the plant) for sugar production through photosynthesis.

Anybody care to rewrite? 78.146.157.252 (talk) 13:23, 18 July 2009 (UTC)Reply

Photorespiration

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I removed the citation need from the paragarph: "C3 plants lose up to 97% of the water..." because the wikipedia article on Photorespiration addresses these things and citations and references can be found there. Linkato1 (talk) 16:20, 28 August 2019 (UTC)Reply

Assessment comment

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The comment(s) below were originally left at Talk:C3 carbon fixation/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Comment(s)Press [show] to view →

Plants that survive solely on C3 fixation (C3 plants) tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, carbon dioxide concentrations are around 200 ppm or higher, and ground water is plentiful. The C3 plants, originating during Mesozoic and Paleozoic era, predate the C4 plants and still represent approximately 95% of Earth's plant biomass.

C3 plants must be in areas with high concentrations of carbon dioxide because RuBisCO often incorporates an oxygen molecule into the RuBP, instead of a carbon dioxide molecule. This breaks the RuBP into a three-carbon sugar that can remain in the Calvin cycle, and two molecules of glycolate which is oxidized into carbon dioxide, wasting the cell's energy. High concentrations of carbon dioxide lowers the chance that RuBisCO incorporates an oxygen molecule. C4 and CAM plants have adaptations that allow them to survive in areas where the plant cannot take in a lot of carbon dioxide.

The article, as currently written, contains inaccuracies regarding carbon dioxide concentrations.

Hot dry days cause C3 plants to close their stomata, starving the plant of CO2. This in turn causes O2 concentrations within the plant to exceed that of CO2, which causes photorespiration to occur. The result of this process is no food production and reduced carbon fixation.

If CO2 is the cause of climate change, and climate change is causing hot dry days, then this is another example of CO2 accumulation reinforcing itself.

35.9.40.68 00:08, 30 August 2007 (UTC)Reply

Last edited at 00:08, 30 August 2007 (UTC). Substituted at 10:38, 29 April 2016 (UTC)