How does isocitrate become alpha-ketoglutarate?
This is a two-step process, which involves oxidation of isocitrate (a secondary alcohol) to oxalosuccinate (a ketone), followed by the decarboxylation of the carboxyl group beta to the ketone, forming alpha-ketoglutarate.
What enzyme converts isocitrate to alpha-ketoglutarate?
Isocitrate dehydrogenase (IDH)
Isocitrate dehydrogenase (IDH) converts cellular isocitrate to α-ketoglutarate through oxidative decarboxylation .
What occurs when isocitrate is converted into alpha-ketoglutarate?
Isocitrate undergoes oxidative decarboxylation, producing the 5-carbon α-ketoglutarate. Oxidative decarboxylation produces free CO2 and NADH. α-Ketoglutarate dehydrogenase. The 5-carbon α-ketoglutarate undergoes oxidative decarboxylation to succinyl-CoA.
What reaction does isocitrate dehydrogenase catalyze?
Isocitrate dehydrogenase is a digestive enzyme that is used in the citric acid cycle. Its main function is to catalyze the oxidative decarboxylation of isocitrate into alpha-ketoglutarate.
Is isocitrate to alpha-ketoglutarate reversible?
Isocitrate Dehydrogenase. Isocitrate dehydrogenase (IDH) is an important enzyme in the tricarboxylic acid cycle, which occurs in the mitochondrial matrix. IDH is responsible for catalyzing the reversible conversion of isocitrate to alpha-ketoglutarate and CO2 in a two-step reaction (14).
How is alpha-ketoglutarate produced?
α-Ketoglutarate can be produced by: Oxidative decarboxylation of isocitrate by isocitrate dehydrogenase. Oxidative deamination of glutamate by glutamate dehydrogenase. From galacturonic acid by the organism Agrobacterium tumefaciens.
Does Alpha-ketoglutarate dehydrogenase contain Lipoamide?
Lipoamide dehydrogenase is not unique for α-KGDH, it is also a component of PDH and branched-chain ketoacid dehydrogenase.
What type of reaction is catalyzed by isocitrate dehydrogenase and α ketoglutarate dehydrogenase?
What type of reaction is catalyzed by isocitrate dehydrogenase and α-ketoglutarate dehydrogenase? Both dehydrogenases are involved in redox reactions in which a CO2 is abstracted from a substrate. In both cases NAD+ is reduced while the other substrate is oxidized.
Is isocitrate oxidized or reduced?
Step 3 (isocitrate to alpha-ketoglutarate) is an oxidation of an alcohol to a ketone (NAD+ gets reduced to NADH) as well as a decarboxylation (elimination of CO2).
What is the role of α-ketoglutarate?
Alpha-ketoglutarate (AKG) is a key molecule in the Krebs cycle determining the overall rate of the citric acid cycle of the organism. It is a nitrogen scavenger and a source of glutamate and glutamine that stimulates protein synthesis and inhibits protein degradation in muscles.
What does Alpha ketoglutarate dehydrogenase do?
Alpha-ketoglutarate dehydrogenase (α-KGDH) is a highly regulated enzyme, which could determine the metabolic flux through the Krebs cycle. It catalyses the conversion of α-ketoglutarate to succinyl-CoA and produces NADH directly providing electrons for the respiratory chain.