Fig. 6.

Reactions in the Krebs cycle influenced by low or high concentrations of H₂O₂. In the presence of low concentrations of H₂O₂, (a) when aconitase is completely inactivated but α-KGDH is still functional, glutamate becomes a key metabolite driving a segment of the Krebs cycle (thick arrows) and NADH production is maintained. When α-KGDH is also partially inhibited (b) in the presence of higher concentrations of H₂O₂ (≥100 μm), NADH generation becomes limited, resulting in an impaired respiratory capacity.