Citric acid cycle

The citric acid cycle is found in the cytosol of aerobic prokaryotes and in the mitochondria of eukaryotes. Anaerobic organisms have incomplete cycles while facultative aerobic organisms only have a functional citric acid cycle in the presence of oxygen.  This is well described in Instant Notes in Biochemistry. Important intermediates for fatty acid synthesis, nucleotide synthesis and amino acid synthesis are generated by the citric acid cycle.