TLS Online TPP Program

#Id: 353

#Unit 1. Molecules and their Interaction Relevant to Biology

Transketolase requires the cofactor thiamine pyrophosphate (TPP)

TLS Online TPP Program

#Id: 354

#Unit 1. Molecules and their Interaction Relevant to Biology

Acetyl-CoA and NADH are potent allosteric inhibitors of the enzyme. 

TLS Online TPP Program

#Id: 355

#Unit 1. Molecules and their Interaction Relevant to Biology

Acetyl-CoA inhibits the transacetylase component whereas NADH inhibits the dihydrolipoyl dehydrogenase component. 

TLS Online TPP Program

#Id: 356

#Unit 1. Molecules and their Interaction Relevant to Biology

The reaction catalyzed by citrate synthase is essentially a Claisen condensation, involving a thioester (acetyl-CoA) and a ketone (oxaloacetate)

TLS Online TPP Program

#Id: 359

#Unit 1. Molecules and their Interaction Relevant to Biology

Eukaryotic cells have two isozymes of aconitase

• The mitochondrial isozyme (convert citrate to isocitrate in the citric acid cycle)

• The cytosolic isozyme 

TLS Online TPP Program

#Id: 360

#Unit 1. Molecules and their Interaction Relevant to Biology

The cytosolic isozymes has two distinct function, It catalyzes the conversion of citrate to isocitrate, providing the substrate for a cytosolic isocitrate dehydrogenase that generates NADPH as reducing power for fatty acid synthesis and other anabolic processes in the cytosol. It also has a role in cellular iron homeostasis