Figure 1.

mROS production sites and mitochondrial electron transfer process. The mROS generation sites can be divided into two categories, namely NADH/NAD⁺ equipotential group (yellow) and the UQH₂/UQ equipotential group (blue). The NADH/NAD⁺ group consists of KGDH, PDH, BCKDH, OADH, and complex I. The UQH₂/UQ isopotential group is made up of complex II, PRODH, DHODH, ETFQO, and complex III. Complex I uses two equipotential groups to form reactive oxygen species. The red line indicates the electron transfer process of the mitochondria. mROS, mitochondrial reactive oxygen species; UQH₂, ubisemiquinone; UQ, ubiquinone; KGDH, α-ketoglutarate dehydrogenase; PDH, pyruvate dehydrogenase; BCKDH, branched chain keto acid dehydrogenase; OADH, 2-oxoadipate dehydrogenase; PRODH, proline dehydrogenase; DHODH, dihydroorotate dehydrogenase; and ETFQO, electron transferring flavoprotein ubiquinone oxidoreductase.