Question

For each of the four respiratory complexes, list the redox centers and their reduction potentials. What is the significance of the order each redox center is used in electron transport?

Answer 1

The four respiratory complexes are:

1.NADH-CoQ Reductase

2.Succinate-CoQ Reductase.

3.CoQH2-cytochrome c Reductase.

4.Cytochrome c Oxidase.

The electron transfer with the help of oxidation and reduction reaction in the particular complex of the electron transport chain is termed as their redox centers.

The redox centers of the given four complexes are:

Respiratory complex	Redox centers	Reduction potential
NADH-CoQ Reductase	FMN and Fe/S	0.38 V
Succinate-CoQ Reductase.	FAD and Fe/S	0.03 V
CoQH2- cytochrome c Reductase.	Hemes (bL, bH, and c1) and Fe/S	0.194 V
Cytochrome c Oxidase.	Hemes (a and a3) and copper atoms (CuA and CuB)	0.562 V

Significance of the redox center in the electron transport:

The redox proteins involved in the redox centers plays a significant role as the catalytic components. There is a significant role of electrostatic interactions in modulating the redox potentials of complexed electron transfer protein. The electron transfer takes place in an activated complex in which, the donor and acceptor centers have the same redox potential. So, redox centers help in maintaining the redox potential in the electron transport.