Figure 1.A simple diagram depicting electron transport in mammalian cells. The redox
potential increases as the electrons move through each complex located in
the inner membrane of the mitochondria. NADH, an electron donor, donates
two electrons. The electrons flow through the four complexes causing
hydrogen (H+) to be pumped across the inner mitochondrial
membrane to favor free energy. At each step, the free electron can be
picked up by oxygen (O2), which will convert O2 to
superoxide, a highly reactive oxygen species (ROS). Electron transfer can
be blocked at the complexes by several different compounds. Antimycin A
blocks transfer of electrons at complex III.
