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.
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.
Acetyl-CoA is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle to be oxidized for energy production.
Malic acid is an organic compound with the molecular formula HO2CCH(OH)CH2CO2H. It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms, though only the L-isomer exists naturally. The salts and esters of malic acid are known as malates. The malate anion is a metabolic intermediate in the citric acid cycle.
Oxaloacetic acid (also known as oxalacetic acid or OAA) is a crystalline organic compound with the chemical formula HO2CC(O)CH2CO2H. Oxaloacetic acid, in the form of its conjugate base oxaloacetate, is a metabolic intermediate in many processes that occur in animals. It takes part in gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, fatty acid synthesis and the citric acid cycle.
Sodium fluoroacetate, also known as compound 1080, is an organofluorine chemical compound with the chemical formula FCH2CO2Na. It is the sodium salt of fluoroacetic acid. It contains sodium cations Na+ and fluoroacetate anions FCH2CO−2. This colourless salt has a taste similar to that of table salt and is used as a rodenticide.
Fluoroacetate may refer to:
Fatty acid metabolism consists of various metabolic processes involving or closely related to fatty acids, a family of molecules classified within the lipid macronutrient category. These processes can mainly be divided into (1) catabolic processes that generate energy and (2) anabolic processes where they serve as building blocks for other compounds.
Aconitase is an enzyme that catalyses the stereo-specific isomerization of citrate to isocitrate via cis-aconitate in the tricarboxylic acid cycle, a non-redox-active process.
The enzyme citrate synthase E.C. 2.3.3.1 ] exists in nearly all living cells and stands as a pace-making enzyme in the first step of the citric acid cycle. Citrate synthase is localized within eukaryotic cells in the mitochondrial matrix, but is encoded by nuclear DNA rather than mitochondrial. It is synthesized using cytoplasmic ribosomes, then transported into the mitochondrial matrix.
Fluoroacetic acid is a organofluorine compound with the chemical formula FCH2CO2H. It is a colorless solid that is noted for its relatively high toxicity. The conjugate base, fluoroacetate occurs naturally in at least 40 plants in Australia, Brazil, and Africa. It is one of only five known organofluorine-containing natural products.
Ammonium ferric citrate has the formula [NH+4]5[Fe(C6H4O7)2]5−. The iron in this compound is trivalent. All three carboxyl groups and the central hydroxyl group of citric acid are deprotonated. A distinguishing feature of this compound is that it is very soluble in water, in contrast to ferric citrate which is not very soluble.
In enzymology, a citrate—CoA ligase is an enzyme that catalyzes the chemical reaction
Dichapetalum cymosum, commonly known as gifblaar from Afrikaans, or occasionally by its English translation, poison leaf, is a small prostrate shrub occurring in northern parts of Southern Africa in the family Dichapetalaceae. It is notable as a common cause of lethal cattle poisoning in this region and is considered one of the 'big 6' toxic plants of cattle in South Africa. A 1996 estimate of plant poisonings in South Africa attributes 8% of cattle mortality caused by poisonous plants to it. The majority (70%) of fatal cases are in Limpopo province, with 10% each in North West, Mpumalanga, and Gauteng. Fluoroacetate, the poison used to synthetically produce Compound 1080 used extensively in New Zealand, occurs in all parts of the plant and is responsible for the toxic effects shown.
1,3-Difluoro-2-propanol is a metabolic poison which disrupts the citric acid cycle and is used as a rodenticide, similar to sodium fluoroacetate. It is the main ingredient in the rodenticide product Gliftor which was widely used in the former USSR and still approved in China.
Fluoroacetyl chloride is an acyl chloride.
Methyl fluoroacetate (MFA) is an organic compound with the chemical formula FCH2CO2CH3. It is an extremely toxic methyl ester of fluoroacetic acid. It is a colorless, odorless liquid at room temperature. It is used as a laboratory chemical and as a rodenticide. Because of its extreme toxicity, MFA was studied for potential use as a chemical weapon.
Fluoroethyl fluoroacetate, or more accurately 2-fluoroethyl fluoroacetate, is an organic compound with the chemical formula FCH2CO2CH2CH2F. It is the fluoroacetate ester of 2-fluoroethanol, or in other words, the 2-fluoroethyl ester of fluoroacetic acid. 2-Fluoroethyl fluoroacetate is two times more toxic than methyl fluoroacetate.
The citrate-malate shuttle is a series of chemical reactions, commonly referred to as a biochemical cycle or system, that transports acetyl-CoA in the mitochondrial matrix across the inner and outer mitochondrial membranes for fatty acid synthesis. Mitochondria are enclosed in a double membrane. As the inner mitochondrial membrane is impermeable to acetyl-CoA, the shuttle system is essential to fatty acid synthesis in the cytosol. It plays an important role in the generation of lipids in the liver.
2-Ethylhexyl fluoroacetate is an organic compound with the chemical formula FCH2CO2CH2CH(CH2CH3)CH2CH2CH2CH3. It is the fluoroacetate ester of 2-ethylhexanol, in other words, the 2-ethylhexyl ester of fluoroacetic acid. It can be produced by reaction of ethyl fluoroacetate with 2-ethylhexanol. 2-Ethylhexyl fluoroacetate is a liquid that is highly toxic by skin absorption.
