ISSUE:

Hi everyone, I was studying biology and I got stuck trying to understand how electrons move in that molecule called FAD. That is, my question is not related to the molecule or how the metabolic pathways work. My question is expressly focused on the oxidation and reduction of these nitrogens. I try to explain myself:

In other words, even the little I know about chemistry haha ​​oxidation is loss of electrons and reduction gain, but in the drawing on the left I see nitrogen with 3 bonds (and 2 electrons I suppose they are not shown, with capacity for 1 coordinate bond)


The truth is I don't see where the "loss" of electrons is in nitrogen or why they call it oxidized, in the same way... I don't understand that when a hydrogen is coupled to it it "reduces" since it is supposed to share its pair of electrons to make a coordinated bond in reality I would be losing electrons, not gaining them... I don't know if I'm explaining myself?

the truth is that I try to follow the path of the electrons and I don't see it.

On the other hand, above they give the example of AH2 that releases 2 electrons and 2 protons into the environment? It is not clear to me, that is, it is not supposed that in the dissociation of an acid, for example, although this is from Lewis's perspective, even so, in this case, having hydrogen would be releasing H+ into the medium with which the other spice would remain charged as A- which, according to the image, does not occur..... according to the image, 2e- and 2H+ are released into the medium, which on the other hand, I do not believe that electrons exist as "free species", right?

The truth is that I have made a cocoa, I hope you can help me ... thank you very much

all the best!