The citric acid cycle—also known as the Krebs cycle, Szent–Györgyi–Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of biochemical reactions to release the energy stored in nutrients through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. The chemical energy released is available under the form of ATP. The Krebs cycle is used by organisms that respire (as opposed to organisms that ferment) to generate energy, either by anaerobic respiration or aerobic respiration. In addition, the cycle provides precursors of certain amino acids, as well as the reducing agent NADH, that are used in numerous other reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest components of metabolism. Even though it is branded as a "cycle", it is not necessary for metabolites to follow only one specific route; at least three alternative segments of the citric acid cycle have been recognized.
The green sulfur bacteria are a phylum, Chlorobiota, of obligately anaerobic photoautotrophic bacteria that metabolize sulfur.
Biological carbon fixation, or сarbon assimilation, is the process by which living organisms convert inorganic carbon to organic compounds. These organic compounds are then used to store energy and as structures for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use chemosynthesis in the absence of sunlight. Chemosynthesis is carbon fixation driven by chemical energy rather than from sunlight.
The oxoglutarate dehydrogenase complex (OGDC) or α-ketoglutarate dehydrogenase complex is an enzyme complex, most commonly known for its role in the citric acid cycle.
The reverse Krebs 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.
In enzymology, a phytochromobilin:ferredoxin oxidoreductase is an enzyme that catalyzes the chemical reaction
In enzymology, a taurine dioxygenase (EC 1.14.11.17) is an enzyme that catalyzes the chemical reaction.
In enzymology, an L-2-hydroxyglutarate dehydrogenase is an enzyme that catalyzes the chemical reaction
In enzymology, a 2-oxobutyrate synthase (EC 1.2.7.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-methyl-2-oxobutanoate dehydrogenase (ferredoxin) (EC 1.2.7.7) is an enzyme that catalyzes the chemical reaction
In enzymology, a carbon-monoxide dehydrogenase (ferredoxin) (EC 1.2.7.4) is an enzyme that catalyzes the chemical reaction
In enzymology, a glyceraldehyde-3-phosphate dehydrogenase (ferredoxin) (EC 1.2.7.6) is an enzyme that catalyzes the chemical reaction
In enzymology, an indolepyruvate ferredoxin oxidoreductase (EC 1.2.7.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a pyruvate synthase is an enzyme that catalyzes the interconversion of pyruvate and acetyl-CoA. It is also called pyruvate:ferredoxin oxidoreductase (PFOR).
In enzymology, a glutamate synthase (ferredoxin) (EC 1.4.7.1) is an enzyme that catalyzes the chemical reaction
In enzymology, a glutamate synthase (NADPH) (EC 1.4.1.13) is an enzyme that catalyzes the chemical reaction
In enzymology, a saccharopine dehydrogenase (NADP+, L-lysine-forming) (EC 1.5.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a 2-hydroxy-3-oxoadipate synthase (EC 2.2.1.5) is an enzyme that catalyzes the following chemical reaction:
In enzymology, a succinylornithine transaminase (EC 2.6.1.81) is an enzyme that catalyzes the chemical reaction
In enzymology, an aldehyde ferredoxin oxidoreductase (EC 1.2.7.5) is an enzyme that catalyzes the chemical reaction
