Now, in this particular case, I've drawn ten of these individual C subunits that form this cring. And we have the A subunit that is found in close proximity to this C ring. Now, if we zoom in onto this A subunit this is basically what we're going to see. Now, even though we don't exactly know what the structure of the A subunit actually looks like this is what we believe the structure looks like. So the structure of the A subunit seems to consist of two hydrophilic half channels that do not span the entire membrane of the A subunit. One of these half channels is open to the matrix side while the other one is open to the intermembrane side.