In mitochondria, what is the mechanism by which electrons are transferred between different cytochromes?

Question

And how is the energy gained from the lowering of the "energy level" of the electron used to generate the chemiosmotic gradient?

Answer 1

Yes it is a redox reaction but the electrons are "pulled" by an increasing electronegativity with the final electron acceptor being oxygen (the most electronegative). Water is formed in this process.

Answer 2

I believe the mechanism you are searching for is what we know as 'Redox' reactions. Through the reduction and subsequent oxidation of molecules moving down an energy gradient, energy is released, thus favoring movement of the electron.