The Reductive/Reverse TCA Cycle (rTCA cycle). Shown are all of the reactants, intermediates and products for this cycle.
The reverse Krebs cycle (also known as the reverse tricarboxylic acid cycle, the reverse TCA cycle, or the reverse citric acid cycle, or the reductive tricarboxylic acid cycle, or the reductive TCA cycle)
is a sequence of chemical reactions that are used by some bacteria to produce carbon compounds from carbon dioxide and water by the use of energy-rich reducing agents as electron donors.
The reaction is the citric acid cycle run in reverse. Where the Krebs cycle takes carbohydrates and oxidizes them to CO2 and water, the reverse cycle takes CO2 and H2O to make carbon compounds.
This process is used by some bacteria (such as Aquificota) to synthesize carbon compounds, sometimes using hydrogen, sulfide, or thiosulfate as electron donors.[1][2] This process can be seen as an alternative to the fixation of inorganic carbon in the reductive pentose phosphate cycle which occurs in a wide variety of microbes and higher organisms.
^Evans MC, Buchanan BB, Arnon DI (April 1966). "A new ferredoxin-dependent carbon reduction cycle in a photosynthetic bacterium". Proceedings of the National Academy of Sciences of the United States of America. 55 (4): 928–934. Bibcode:1966PNAS...55..928E. doi:10.1073/pnas.55.4.928. PMC 224252. PMID 5219700.
^Buchanan BB, Arnon DI (1990). "A reverse KREBS cycle in photosynthesis: consensus at last". Photosynthesis Research. 24: 47–53. doi:10.1007/BF00032643. PMID 11540925. S2CID 2753977.
and 26 Related for: Reverse Krebs cycle information
The reverseKrebscycle (also known as the reverse tricarboxylic acid cycle, the reverse TCA cycle, or the reverse citric acid cycle, or the reductive...
such as glucose. In other bacteria, different mechanisms like the reverseKrebscycle are used to achieve the same end. The first photosynthetic organisms...
carbon from carbon dioxide to synthesize carbon compounds through reverseKrebscycle. International Union of Pure and Applied Chemistry (2005). Nomenclature...
Carbon fixation occurs via the Calvin Benson Bassham cycle and possibly the reverseKrebscycle. "Thiomargarita". NCBI taxonomy. Bethesda, MD: National...
diffuses back to the bundle sheath to complete the reductive pentose phosphate cycle (RPP). This exchange of metabolites is essential for C4 photosynthesis to...
Calvin cycle or another metabolic pathway called the 3-hydroxypropionate/ 4-hydroxybutyrate cycle. The Thermoproteota also use the reverseKrebscycle while...
organic carbon is produced through photosynthesis. Respiration is the reverse process and consumes organic carbon to produce inorganic carbon. Photosynthesis...
is even inferred that LUCA also grew from H2 and CO2 via the reverse incomplete Krebscycle. Other metabolic pathways inferred in LUCA are the pentose phosphate...
protocell growth. Metabolic reactions in the Wood-Ljungdahl pathway and reverseKrebscycle have been produced in acidic conditions and thermophilic temperatures...
nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygen cycle, among others that continually...
The carbon cycle is that part of the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere...
Photorespiration (also known as the oxidative photosynthetic carbon cycle or C2 cycle) refers to a process in plant metabolism where the enzyme RuBisCO...
carbon sink. The phenomenon of whales defecating near the water's surface reverses the typical flow of nutrients in the ocean's biological pump, contributing...
reduction of nitrate or oxygen. Autotrophic Campylobacterota use the reverseKrebscycle to fix carbon dioxide into biomass, a pathway originally thought...
be used to reduce atmospheric CO2 concentrations, which could partially reverse the warming that has already occurred by that date. All emission pathways...
ecosystem. Soil carbon is a carbon sink in regard to the global carbon cycle, playing a role in biogeochemistry, climate change mitigation, and constructing...
bacterium utilizes a special form of the reductive tricyclic acid cycle (ReverseKrebscycle) to fix CO2. Various metabolic processes were examined on a 1...
carbon cycle. Studies show that microbes in the deep ocean are not dormant, but are metabolically active and must be participating in nutrient cycling by...
decompose partially or completely. This breakdown process can be viewed as the reverse of photosynthesis. These resulting units can then polycondense to form...
buffer that prevents drastic changes in acidity (or pH). The marine carbon cycle also affects the reaction and dissolution rates of some chemical compounds...
000 years". They found that prior to approximately 900,000 years ago, the cycle of ice ages followed by relatively short warm periods lasted about 40,000...
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