Draw a labelled diagram of the structure of a mitochondrion as seen under the electron microscope.

Explain how the structure of a mitochondrion is related to its function.

Award [1] for two correct labels. Structures must be drawn correctly for mark to be awarded.
outer membrane – drawn as a continuous line;
inner membrane – showing folding to create cristae;
cristae – shown as distinct infoldings of inner membrane;
matrix;
intermembrane space – shown as continuous space between outer and inner membranes;
(70S) ribosomes – shown as small dots in proportion with organelle, not too large;
(naked) loop of DNA;

a. matrix is site of reactions of Krebs cycle;
b. thin intermembrane space to build up high proton concentration/[H⁺];
c. ATP synthase/respiratory complex on inner membrane to produce ATP as protons pass back to matrix;
d. folded inner membrane / cristae to increase surface area (for electron transport chain);
e. ribosomes to make enzymes/proteins (required for Krebs cycle);

There was a very wide range of drawings, many well drawn and labeled, but more that were highly inaccurate. Quite often cristae were drawn as separate entities, rather than as extensions of the inner membrane.

If the drawing was poor, then 8(b) on structure vs function was also poorly answered.  This was an opportunity to show in-depth knowledge of aerobic respiration.