Oxidation

[blackbird27]

I am a little bit confused by the biological oxidation. It is performed by the release of hydrogen instead of addition oxygen, right? And hydrogen acts as a proton. So why is NAD reduced instead of oxidized when it becomes positive? And following this logic, in biological oxidation are reducers donors, and oxidisers - acceptors of electrons? The respiratory chain carries electrons to the ultimate oxidizer - oxygen but aren't these electrons in fact the positively charged hydrogens from NAD.H2.
I know that these is a shambolic sum of questions but I'd be really grateful if you'd find the time to explain their answers to me.
Thanks!

[JackBean]

The oxidation can be performed by either release of hydrogen or addition of oxygen.
NAD+ is oxidized and it can become reduced NADH.
Yes, they are. Actually no, they are not, because electrons are not hydrogens. During redox reactions electrons are transferred. The hydrogens in NAD(P)/FAD are there only to make it electroneutral.

[blackbird27]

Thanks