Fig. 2
From: On the physiological and cellular homeostasis of ascorbate
Ascorbate distribution in mitochondria. In the cytoplasm where pH = 7.2 ascorbate concentration is maintained by SVCT transporters in the plasma membrane. In the periplasm, where pH < 7.2, high proton concentration will produce Casc > 1 mM. In the mitochondria matrix the ascorbate concentration will be effectively suppressed by the highly negative electrostatic potential across inner mitochondria membranes. Mitochondria contain SVCT2, indicating that the ascorbate distribution is rigorously maintained