Isocitrate Dehydrogenase

The video explains the mechanism of isocitrate dehydrogenase, focusing on its role in oxidative decarboxylation. It details the conversion of isocitrate to alpha-ketoglutarate, highlighting the involvement of cofactors like manganese and NAD+/NADP+. The process involves oxidation, decarboxylation, and stabilization of intermediates, with a critique of a reaction diagram to clarify the sequence of events.

What is the primary role of manganese in the isocitrate dehydrogenase reaction?

• To catalyze the reaction

• To provide electrons

• To stabilize the enolate intermediate

• To act as a substrate

Which molecule is reduced during the oxidative decarboxylation process?

• ADP

• ATP

• FAD

• NAD+

What is the role of the base in the active site of isocitrate dehydrogenase?

• To perform a proton transfer

• To donate a proton

• To stabilize the substrate

• To bind to manganese

What is the name of the intermediate stabilized by manganese ions?

• Alpha-ketoglutarate

• Oxalosuccinate

• Citrate

• Isocitrate

What happens to the enolate formed during the reaction?

• It releases energy

• It quickly collapses

• It remains stable

• It forms a new bond

What is the final product of the isocitrate dehydrogenase reaction?

• Citrate

• Alpha-ketoglutarate

• Oxaloacetate

• Succinate

How many carbon atoms are present in alpha-ketoglutarate?

• Four

• Five

• Six

• Seven

Which enzyme complex consumes alpha-ketoglutarate?

• Alpha-ketoglutarate dehydrogenase complex

• Isocitrate lyase

• Pyruvate dehydrogenase complex

• Citrate synthase

What is the significance of the decarboxylation step in the reaction?

• It generates ATP

• It stabilizes the enzyme

• It removes a carbon atom

• It adds a carbon atom

What is the initial carbon count of isocitrate before the reaction?

• Four

• Five

• Six

• Seven