And now this H plus ion can move from this area to an area where we have a low proton concentration in the matrix of the mitochondria. And in this fashion we see that the movement of these protons from the high concentration to the low concentration basically powers the movement of this C rink. So once again in diagram one an H plus ion will enter the half channel of the A subunit facing the intermembrane space and it will bind to that aspartate residue of the nearby C subunit. And once the binding takes place it transforms aspartate 61 of that particular C subunit into a spartic acid. Because a spartic acid is more hydrophobic it wants to move into the core of that inner membrane of the mitochondria and out of this half channel. And so as that rotation takes place it causes the entire serring to actually rotate.