Cellular respiration occurs in the cytoplasm and mitochondria of each eukaryotic cell. The process of glycolysis takes place within the cytoplasm, and the TCA (or Krebs) cycle and oxidative phosphorylation takes place in the inner membrane and matrix of the mitochondria. All prokaryotes lack mitochondria, and thus cellular respiration occurs within the cell membrane or cytoplasm. The Electron Transport Chain occurs within the plasma membrane in prokaryotes and oxidative phosphorylation occurs within the cytoplasm.