Enzymes are the proteins which speed up the rate of a chemical reaction in a living organism. All enzymes of TCA cycle are located in the mitochondrial matrix, except one which is located in the inner mitochondrial membranes in eukaryotes and in the cytosol in prokaryotes. This enzyme is

Mitochondrion is the organelle which bears various enzymes participating in Krebs cycle. Each mitochondrion is covered by a double membrane. The inner membrane is selectively permeable and forms foldings called cristae. The inner membrane bears oxysomes, enzymes of fatty acids, succinate dehydrogenase (of Krebs cycle) and the electron transport system. All other enzymes of Krebs cycle are present in the mitochondrial matrix.