Enzymes of Krebs cycle occur in mitochondrial matrix except one which is attached to inner mitochondrial membrane

Enzymes of the Krebs cycle occur in the mitochondrial matrix except one that is Succinate dehydrogenase which is attached to inner mitochondrial membrane.
Succinate dehydrogenase is an enzyme complex, found in many bacterial cells and the inner mitochondrial membrane of eukaryotes.
It is the only enzyme that participates in both the citric acid cycle and the electron transport chain. The reactions occur in the inner mitochondrial membrane by coupling the two reactions together.