Carbon-based life: Difference between revisions

Because it is lightweight and relatively small in size, carbon molecules are easy for [[enzyme]]s to manipulate. [[Carbonic anhydrase]] is part of this process. Carbon has an [[atomic number]] of 6 on the [[periodic table]]. The [[carbon cycle]] is a [[biogeochemical cycle]] that is important in maintaining life on Earth over a long time span. The cycle includes [[carbon sequestration]] and [[carbon sink]]s.<ref name="nasacc">{{cite web|last1=Riebeek|first1=Holli|title=The Carbon Cycle|url=http://earthobservatory.nasa.gov/Features/CarbonCycle/?src=eoa-features|website=Earth Observatory|publisher=NASA|access-date=5 April 2018|date=16 June 2011|archive-url=https://web.archive.org/web/20160305010126/http://earthobservatory.nasa.gov/Features/CarbonCycle/?src=eoa-features|archive-date=5 March 2016|url-status=live|df=dmy-all}}</ref><ref>{{cite book|last1=Archer|first1=David|title=The global carbon cycle|date=2010|publisher=Princeton University Press|location=Princeton|isbn=9781400837076}}</ref> [[Plate tectonics]] are needed for life over a long time span, and carbon-based life is important in the plate tectonics process.<ref>{{Cite web|url=https://www.sydney.edu.au/news-opinion/news/2022/05/26/how-plate-tectonics-have-maintained-earth-s--goldilocks--climate.html|title=How plate tectonics have maintained Earth's 'Goldilocks' climate|website=The University of Sydney}}</ref> An abundance of iron- and sulfur -based [[Anoxygenic photosynthesis]] life forms that lived from 3.80 to 3.85 billion years ago on Earth produces an abundance [[black shale]] deposits. These shale deposits increase heat flow and crust buoyancy, especially on the sea floor, helping to increase plate tectonics. [[Talc]] is another organic mineral that helps drive plate tectonics.<ref>{{Cite web|url=https://www.soapstonetalc.com/talc-processing/|title=Talc Processing|website=www.soapstonetalc.com}}</ref><ref>{{Cite web|url=http://eos.org/research-spotlights/talc-may-make-mexicos-subduction-zone-more-slippery|title=Talc May Make Mexico's Subduction Zone More Slippery|first=Aaron|last=Sidder|date=August 23, 2023|website=Eos}}</ref> [[Inorganic chemistry|Inorganic processes]] also help drive plate tectonics.<ref>{{Cite web|url=https://www.researchgate.net/publication/250164952|title=Geology, Age and Origin of Supracrustal Rocks at Akilia, West Greenland}}</ref> Carbon-based [[photosynthesis]] life caused a rise in [[oxygen]] on Earth. This increase of oxygen helped plate tectonics form the first continents.<ref>{{Cite web|url=https://www.forbes.com/sites/davidbressan/2023/03/07/first-continents-and-weathering-iron-minerals-helped-rise-oxygen-levels-on-early-earth/|title=Rise Of Oxygen On Early Earth Linked To The Formation Of First Continents|first=David|last=Bressan|website=Forbes}}</ref> It is frequently assumed in [[astrobiology]] that if life exists elsewhere in the [[Universe]], it will also be carbon-based.<ref name=BC>{{cite web | url = http://biocab.org/Astrobiology.html | title = Astrobiology | access-date = 2011-01-17 | date = September 26, 2006 | publisher = Biology Cabinet}}</ref><ref>{{cite web |url=http://library.thinkquest.org/C003763/index.php?page=interview07 |title=Polycyclic Aromatic Hydrocarbons: An Interview With Dr. Farid Salama |access-date=2008-10-20 |year=2000 |work=Astrobiology magazine |url-status=dead |archive-url=https://web.archive.org/web/20080620075201/http://library.thinkquest.org/C003763/index.php?page=interview07 |archive-date=2008-06-20 }}</ref> Critics, like [[Carl Sagan]] in 1973, refer to this assumption as [[carbon chauvinism]].<ref name =darling>{{cite web |url= http://www.daviddarling.info/encyclopedia/C/carbon-based_life.html |title=Carbon-based life |access-date=14 September 2007 |first=David|last=Darling |publisher=Encyclopedia of Life}}</ref>