I'm currently reviewing this concept in cellular respiration. The book which I'm using is Reece, Minorsky, Campbell's Biology and while it does a good job at explaining the process involved in the electron chain transport. I think it lacks of clearing out my doubts concerning initial protons.
Let me explain, the part where I'm stuck at is, where do originally the protons in the mitochondrial intermembrane space come from?. I understand that there is a proton gradient and the translocation of this protons in the proton pump is key during the electron shuttle process but, how did those initial protons come?. In other words, during the formation of the mitochondria in the cell, have they always been there? or are they part of some bigger molecule and that those protons are detached from them so that there is an initial gradient that triggers the process for the first time?. In other words, how does that initial spark or kick off begins?.
In most animations I've found, the explanations take for granted that the protons are freely moving in the intermembrane space such as here and also here but what do those videos lack is the explanation of how (as mentioned above) do those protons got there in the first place.
I'd like somebody could help me to clear out this doubt. I feel that as an addition to the answer, I'd like to know how does the mitochondria forms in the cell?. Since I believe there might be steps involved, I'd appreciate that the answer could explain those steps so I could easily understand, because as mentioned. I'm still confused on that part as well.