User:MxManatee123/Carbon fixation


 * ***THESE ARE NOTES TO SELF
 * Quotes from each source that may be helpful for edits
 * https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/carbon-fixation
 * "Carbon assimilation by plants and other photosynthetic organisms is a very important event in the global carbon cycle. Plants fix carbon primarily into 3-phosphoglycerate (PGA, a 3-carbon compound) and hence the process is named the C3 photosynthesis or C3 pathway, or Calvin cycle (named after Nobel laureate, Melvin Calvin). The other two variants of photosynthetic carbon assimilation are C4 photosynthesis (or C4 pathway) and crassulacean acid metabolism (CAM). However, the carbon from C4 acids formed initially during these two pathways has to be refixed ultimately through the C3 or Calvin or Benson–Calvin cycle. Thus, the C3 photosynthesis is the basic route of carbon assimilation while the C4 pathway and CAM function as carbon accumulating mechanisms and form adjuncts of the Calvin cycle. Plants possessing only the Benson–Calvin cycle are called C3 plants, while the other two categories include C4 plants and CAM plants."
 * "Carbon assimilation is under the control of the global transcription regulator CreA, which regulates the expression of whole suites of genes encoding catabolic and anabolic pathways of carbon metabolism, as well as cell membrane transporters."
 * "Autotrophic CO2 fixation underlies nearly all biological processes on Earth and has generated reservoirs of prehistorically-fixed carbon, which are currently utilized to satisfy >80% of global energy demand."

"Carbon fixation through the reductive pentose phosphate pathway (Calvin cycle; Fig. 1) is the most biologically abundant pathway"

"7.3.1 Carbon Fixation / Photosynthetic carbon fixation converts light energy into chemical energy. Photosynthesis reduces the carbon in carbon dioxide from OSC = +4 to OSC = +1 in the terminal carbon in glyceraldehyde-3-phosphate, the feedstock for simple sugars, amino acids, and lipids.18 The process (Fig. 7.7) involves four steps in what is known as the Calvin cycle."

The Lead
[From the Talk page] 'From the article: "The Calvin cycle in plants accounts for the preponderance of carbon fixation on land." What does that mean? Is the intended meaning that most of carbon fixed on land is fixed via the Calvin cycle in plants?

Are there any processes other that photosynthesis that fix carbon?

What about carbon fixation by marine animals and micro-organisms? There must be a lot of carbon locked permanently in chalk, limestone and marble. Is this process continuing, and if so, what proportion of anthropogenic carbon is being fixed in this way?'

[From the Article] Carbon fixation or сarbon assimilation is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules. The most prominent example of carbon fixation is photosynthesis; another form known as chemosynthesis can take place in the absence of sunlight.

[The Edit] Carbon Fixation, aka carbon assimilation, is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules.[need source] Carbon is primarily fixed through photosynthesis, but some organisms use a process called chemosynthesis in the absence of sunlight.[need reliable source]

Net vs. Gross CO2 fixation
Notes- This section is very short, breaks up the articles flow, the picture doesn't really fit, and offers opinion. Not written neutrally. Definitely needs to be rewritten and add citations. Maybe move this section? The overview implies CO2 isn't the only form of inorganic carbon fixed, but only talks about CO2

Overview of Pathways
Notes- It only talks about the 6 autotrophic pathways and then has a separate sections for the autotrophic pathways and then mentions the non-autotrophic pathways. I think the overview section should briefly explain that there are autotrophic and nonautotrophic pathways and list them, and then go into the pathways

Oxygenic Photosynthesis // Other autotrophic pathways
Notes- These sections could be combined? Or the overview section needs to better set up these sections