Research Paper Volume 11, Issue 19 pp 8433—8462

Figure 1. Oxidative phosphorylation system (OXPHOS) and biochemical pathways for pyrimidine nucleotide synthesis. OM, IMS, IM, and M code for mitochondrial outer membrane, intermembrane space, mitochondrial inner membrane, and mitochondrial matrix, respectively; ETC, electron transport chain; CI, CIII, CIV, CV and Cyt c code for respiratory complexes I, III, IV, ATP synthase and cytochrome c, respectively; Q, coenzyme Q₁₀; NADH and NAD⁺, reduced and oxidized forms of nicotinamide adenine dinucleotide; H⁺, protons; e^-, electrons; ADP, ATP and Pi, adenosine diphosphate, adenosine triphosphate, and inorganic phosphate; H₂O, water; O₂, oxygen; CAD, carbamoyl phosphate synthetase, aspartate transcarbamylase, dihydroorotase; DHODH, dihydroorotate dehydrogenase; UMPS, uridine monophosphate synthase; HCO₃^-, bicarbonate; Gln, glutamine; Asp, aspartate; DHO, dihydroorotate; O, orotate; PRPP, phosphoribosyl 5’-pyrophosphate; UMP, uridine monophosphate; CMP, cytidine monophosphate; CTP, cytidine triphosphate; UCK2, uridine cytidine kinase 2.