Label the following micrograph of a mitochondrion.

Explain how oxidative phosphorylation occurs by means of chemiosmosis.

Award [1] for any two of the following correctly identified.
I. matrix;
II. inner membrane;
III. cristae / intermembrane space;
IV. outer membrane;

electrons are passed along electron transport system (on inner membrane of mitochondria);
energy is released as electrons move from one carrier to next;
carrier is oxidized as it loses an electron to the next carrier, which becomes reduced;
energy released during electron transport causes proton pumping;
H⁺ pumped against concentration gradient from matrix to intermembrane space;
H⁺ moves down concentration gradient back through inner membrane/ ATP synthase;
passage of H⁺ through ATP synthase causes phosphorylation of ADP/ production of ATP;

Most candidates knew the parts of the mitochondrion.

The question was either very well answered or the answers were very vague.