Now, actually, when this reaction takes place, when our electrons are transferred from NADH to our Ubiquinon to form Ubiquinol, we also actually pump four protons, four H ions from the mitochondrial matrix to the intermembrane space. And so we begin creating our electrochemical gradient. And our flavin mononucleotide also takes up two H ions from our matrix. Now, once Ubiquinol, the reduced version of Ubiquinon, travels to this protein complex number three, what happens is the main function of protein complex number three, also known as our cytochrome reductase or Q cytochrome C oxidore. Reductase basically functions to transfer those electrons from our carrier molecule, the Ubiquinol, to a different electron carrier known as cytochrome C. So cytochrome C is basically a small protein that is water soluble, that carries an electron from protein complex number three to protein complex number four. Now, also when our process within protein complex number three takes place, this pumps two hydrogen atoms from the mitochondrial matrix to our intermembrane space, and that further creates that electrochemical gradient.