In oxidation, there are electron transporters that linked to membrane. And in that electron transporters, there're Iron-Sulphur proteins. And it's reduction potencial is related to "Which way iron's center is buried to protein"

i got it, but how many ways are there? is it like ß or something like that? i'm studying now and that question came to my mind

Mehmet Yeniyapi
Molecular Biology and Genetics
Bulent ecevit univesity / Turkey

I'm not sure I understand your question and its context. Have a read of this article and come back if you have more questions:
https://en.wikipedia.org/wiki/Iron%E2%8 … ur_protein

there is no "up and down" for a single iron ion in the context of its position in a protein.