| Date | May 2013 | Marks available | 2 | Reference code | 13M.3.SL.TZ2.9 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 2 |
| Command term | Distinguish | Question number | 9 | Adapted from | N/A |
Question
Distinguish between oxidation and reduction in biological reactions.
State two products of glycolysis.
1. ..................................................................
2. ..................................................................
Explain the role of cristae in mitochondria.
Markscheme
a. ATP;
b. NADH / H+;
c. three-carbon (atom) compound/pyruvate;
Award [1] for any two of the above.
a. increase the surface area of inner (mitochondrial) membrane; (note: mitochondria is in the stem)
b. allow electron transport because of embedded protein electron carriers;
c. facilitate proton pumping because of high surface to volume ratio/increased surface area;
d. increase ATP production because of ATP synthase/synthatase embedded in membrane;
Examiners report
Part a and b posed no trouble for the well prepared candidates.
Part a and b posed no trouble for the well prepared candidates.
In c marks were lost due to imprecise answers which did not mention that the cristae are on the inner membrane.
