Question 20N.3.hl.TZ0.a
| Date | November 2020 | Marks available | [Maximum mark: 2] | Reference code | 20N.3.hl.TZ0.a |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | a | Adapted from | N/A |
Consider the structures of medicinal molecules in section 37 of the data booklet.
Explain how zanamivir works as a preventative agent against flu viruses.
[2]
«drug» blocks/inhibits «viral» enzyme/neuraminidase/ «activity» ✔
prevents virus from leaving/escaping host cells «thus cannot infect other cells» ✔
Do not accept other anti-viral methods (as question is specific to Zanamivir).
In this question candidates were required to describe how the mixture can be separated by fractional distillation. Only the better candidates scored both marks, though most gained at least one mark, usually for stating that the most volatile component is collected first. Many did not convey the idea that there is continuous evaporation and condensation in the process or the fact that the temperature decreases up the fractionating column.
