What type of reaction does aconitase facilitate?

Aconitase facilitates the isomerization reaction between citrate and isocitrate. In this step of the citric acid cycle, aconitase converts citrate, a six-carbon compound, into isocitrate, which is also a six-carbon compound but has a different structural arrangement. This reaction involves the rearrangement of the hydroxyl and hydrogens on the citrate molecule, resulting in the formation of isocitrate.

Isomerization is a crucial part of the citric acid cycle because it prepares the substrate for subsequent oxidative decarboxylation reactions, which are essential for energy extraction from the metabolic pathway. Aconitase catalyzes the interconversion without the loss of any carbon atoms, allowing for the continuation of the cycle with both compounds effectively participating in energy production later on in the cycle.

The other options present different types of reactions that occur in the cycle but are not facilitated by aconitase. The focus of aconitase is strictly on isomerization during the specific transition from citrate to isocitrate.