Site pages
Current course
Participants
General
Topic 1
Topic 2
Topic 3
Topic 4
Topic 5
Topic 6
Topic 7
Topic 8
Topic 9
Topic 10
Topic 11
Topic 12
Topic 13
Topic 14
Topic 15
Topic 16
Topic 17
Topic 18
Topic 19
Topic 20
Topic 21
Topic 22
Topic 23
Topic 24
Topic 25
Topic 26
Topic 27
3.5.3 Oxidation of Pyruvate to Acetyl CoA
Pyruvate derived from glucose by glycolysis, is oxidatively decarboxylated to acetyl-CoA before entering into citric acid cycle. The reaction is catalysed by multiple enzyme complex pyruvate dehydrogenase, located in the mitochondria. Thiamine pyrophosphate, coenzyme A, lipoic acid and NAD+ are coenzymes needed for the reaction. The acetyl CoA is fed into citric acid cycle and oxidized to CO2 in citric acid cycle. The NADH+H+ is reoxidised to NAD+ via electron transport chain in mitochondria and during this 3 molecules of ATP are synthesized. Four different vitamins required in human nutrition are vital components of this system: thiamine (inTPP), riboflavin (in FAD), niacin (in NAD) and pantothenete (in CoA). The acetyl CoA is fed into citric acid cycle and oxidized to CO2 in citric acid cycle. The NADH+H+ is reoxidised to NAD+ via electron transport chain in
mitochondria and during this 3 molecules of ATP are synthesized.
Pyruvate dehydrogenase CH3COCOOH+ NAD++ CoA-SH→ CH3 COS~CoA+ NADH+H++ CO2Pyruvate Acetyl CoA |