Question 18M.3.sl.TZ1.15
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.sl.TZ1.15 |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | Explain, Suggest | Question number | 15 | Adapted from | N/A |
Antiviral drugs are a major research focus.
Oseltamivir (Tamiflu) and zanamivir (Relenza) are used against flu viruses. Explain how these drugs function.
[2]
blocks/inhibits neuraminidase/NA/«viral» enzyme which allows viruses to pass through cell membrane
prevent virus from leaving/escaping host cell «thus it cannot infect other cells»
[2 marks]
Shikimic acid, the precursor for oseltamivir (Tamiflu), was originally extracted from star anise, and is now produced using genetically modified E. coli bacteria.
Suggest one difficulty associated with synthesizing oseltamivir (Tamiflu) from star anise.
[1]
Any one of:
limited supply of star anise/plant
«star anise» takes time to grow
time-consuming/multi-step extraction
low concentration in plan
Accept “low yield for extraction/conversion” OR “requires environmentally damaging solvents”.
[1 mark]