Now, the most common Ubiquinone molecule in mammals and specifically in humans is coenzyme Q ten. So coenzyme Q ten is basically the specific Ubiquinone that is used by mammals and by humans. Now, once we reduce Ubiquinol to Ubiquinol, ubiquinol then travels from protein complex number one to protein complex number three. 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.