So this is protein complex one. So once again, complex one, also known as NADH dehydrogenase or NADH oxidore ductase, is a very large complex that consists of about 46 individual polypeptide chains. It has an l shape that contains a horizontal component found within the inner membrane and the vertical component that lies within the matrix of the mitochondria. And the transfer of electrons, as we'll see in the future lecture, actually takes place within this vertical component of this complex. Now, the function of the complex is to actually oxidize the NADH back to NAD plus, accept those high energy electrons, and then move those high energy electrons along a specific pathway. And that generates an electric current that basically allows us to pump those H plus ions across the membrane from the matrix and into the intermembrane space.