In Citric acid cycle, which enzyme is inhibited by arsenite?
Ans. is 'b' i.e., a ketoglutarate DehydrogenaseArsenite binds to the sulfhydryl group and hence inhibits the activity of enzymes which have lipoamide in the active site, Hence Arsenite inhibits Pyruvate Dehydrogenase and a ketoglutarate dehydrogenase of citric acid cycle, It is an example for non competitive inhibition, Succinate dehydrogenase is inhibited by malonate.
Isocitrate Dehydrogenase
a ketoglutarate Dehydrogenase
Succinate Dehydrogenase
Aconitase