Question

Paragraph Styles 4. How is FAD regenerated in the pyruvate dehydrogenase complex and why is this unusual? (2 marks)

Answer 1

си-с-соо" fyruvate TPP Cry-C-s-lip-synt CoA-SH Acetyl-lipoamiche Cuscon Dihydrolipoyl transacetylase fyruvate lips Dehydrogenase -SH (PDN) Dihycholipoly / dehydrogenase FAD on NADHTH ° сме си- тер CO2 FAOM2 Oxidized lipoanice NADT 3 ATP

7 - louvate is converted to acetyl coa by Oridative decarboxylation, This is an ireversible reaction, catalysed by a multienzyme Complex, known as pyourate dehydrogen are complex (PDH), which is found only in the mitochondria. + The sequence of reactions catalyze by different enzymes of Pon complex is association with Coentyme. - Pyowate is decarboxylated to give hydroxyethyl TPP, catalyzed by pow. Dihydrolipoyl Hraniacetylase brings about the formation och acetyl lipoamide and then catalyzed the transfer of acetyl group to Coenzyme A to produce acetyl CoA. This cycle is completed when reduced lipoamide is converted to oxidized lipcamide by dihydrolipoyl dehydrogenase transfering the reducing equivalents to FAD. FADH2; intum transfer the reducing equivalents to NAD to - give NADH+H and get converted "back into FAD.