| Date | May 2019 | Marks available | 3 | Reference code | 19M.3.HL:.tz0.22 |
| Level | Higher Level | Paper | Paper 3 | Time zone | time zone 0 |
| Command term | Evaluate | Question number | 22 | Adapted from | N/A |
Question
Discuss the harmful effects of free radicals on cells.
Evaluate the consumption of antioxidants by an athlete.
Markscheme
free radicals can remove electrons from cells / damage cellular membranes / affect cell permeability;
damage to mitochondrial membranes;
impact on DNA by removing electrons «impairing function»;
affect enzymes by removing electrons;
damage contributes to many chronic health problems eg cardiovascular and inflammatory disease / cataract / cancer;
[2 max]
Strengths:
if a pre-existing dietary deficiency exists it may help an athlete;
antioxidants limit the effect of free radicals «usually» by removing their unpaired electron;
possibly reduce the extent of exercise-induced muscle damage;
Limitations:
evidence for benefits is not strong/ convincing/consistent;
high levels of intake of antioxidants has been shown to be harmful;
a lack of adequate regulation of the industry means some products may be poorly formulated and contain banned substances.
Award [2 max] for either strength or limitation.
[3 max]
Examiners report
Was not done as well as had been expected.
Was not done well, students missed key terminology and knowledge and many failed to get full marks. There were many generic answers about antioxidants rather than giving answers specifically related to athletes.
