2ee3- module 11: electron transport and atp synthesis. Electron transport chain, etc, has 5 embedded protein complexes and 2 electron carriers in the inner mitochondrial membrane: complex i, ii, iii, iv, v; coenzyme q and c. Complex i-iv: accept electrons and shuttle them along the etc, and serve as a pump to pump protons out of the mitochondrial matrix into the intermembrane space. Reduction potential: affinity something has for electrons: nadh has the lowest reduction potential at the beginning of etc; oxygen has the highest at the end. Each protein has a redox centre that is reversible reduced and reoxidized through the movement of electrons through them. Each protein complex can have 2+ types of redox centroxygen have an increasing reduction potential as electron passes from i to iii to iv and finally to o2. All redox centres in between nadh and o. Redox centres can be categorized as: coenzymes, fe-s clusters, cytochromes, cu.