Alpha-ketoglutaric acid

Alpha-ketoglutaric acid is a five-carbon keto dicarboxylic acid formed in the citric acid cycle. It also connects cellular energy metabolism with amino-acid synthesis and breakdown.

Citric acid cycle: A metabolic pathway that oxidizes acetyl-CoA to carbon dioxide while generating NADH, FADH₂, and GTP or ATP. Alpha-ketoglutarate is produced from isocitrate and converted to succinyl-CoA within this cycle.
Keto acid: An organic acid containing both a carboxyl group and a ketone group. Alpha-ketoglutarate belongs to this class, with its ketone adjacent to a carboxyl group.
Glutamine metabolism: The synthesis, transport, and breakdown of glutamine in cells and tissues. Glutamine breakdown supplies glutamate, which can be converted into alpha-ketoglutarate.
Isocitrate: A six-carbon tricarboxylic acid intermediate in the citric acid cycle. It precedes alpha-ketoglutarate and differs by one carbon and an additional carboxyl group.
Isocitrate dehydrogenase: An enzyme family that catalyzes oxidative decarboxylation of isocitrate to alpha-ketoglutarate. This enzyme makes alpha-ketoglutarate in a major regulated step of the citric acid cycle.
Dicarboxylic acid: An organic compound containing two carboxyl groups. Its two carboxyl groups give alpha-ketoglutarate its acidic, charged character in cells.
Reductive carboxylation: A metabolic reaction that converts alpha-ketoglutarate to isocitrate using carbon dioxide and reducing power. Some cells use this reversal of the usual cycle direction to support biosynthesis under hypoxia.
2-Hydroxyglutarate: A metabolite formed when alpha-ketoglutarate is reduced, with D and L forms that have distinct biological roles. It resembles alpha-ketoglutarate but can inhibit enzymes that normally use alpha-ketoglutarate.
Alpha-ketoglutarate dehydrogenase complex: A multienzyme complex that oxidatively decarboxylates alpha-ketoglutarate to succinyl-CoA. It consumes alpha-ketoglutarate in the cycle and produces NADH and carbon dioxide.
Glutamate: The deprotonated form of glutamic acid, an amino acid central to nitrogen metabolism and neurotransmission. Adding an amino group to alpha-ketoglutarate produces glutamate.

Linked from 5 pages