And these are the diagrams that correspond to each one of these steps. So let's begin with diagram number one. So again we have the inner mitochondrial membrane. This is the intermembrane space and this is the matrix of the mitochondria. Now we know along the matrix we have a low concentration of protons relative to the intermembrane space because remember, complexes one, three and four of the electron transport chain basically use the movement of electrons to generate that proton electrochemical gradient. So we have a proton rich environment in the intermembrane space and we have a proton poor environment in the matrix of the mitochondria.