Question 20N.3.sl.TZ0.b(ii)
| Date | November 2020 | Marks available | [Maximum mark: 2] | Reference code | 20N.3.sl.TZ0.b(ii) |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | b(ii) | Adapted from | N/A |
Consider the structures of medicinal molecules in section 37 of the data booklet.
Explain, with reference to the action of penicillin, why new penicillins with different side-chains need to be produced.
[2]
bacterial resistance «to older penicillins/antibiotics» ✔
prevent penicillinase/beta-lactamase/enzyme in bacterium to deactivate/open penicillin/beta-lactam ring ✔
Accept “antibiotic resistant bacteria” but not “antibiotic resistance” for M1.
Accept “reduce allergic reactions from from penicillin” for M2.
Award [1 max] for “increased efficiency” OR “increased stability in GIT”.
Do not accept “bacteria develop tolerance”.
Many good answers for M1 but only stronger students managed to score the second one. The answers evidenced again shallow understanding that may result from independent learning. Many students gave answers related to how penicillin causes bacteria to burst which is not related to this question. Once again it shows students perhaps memorizing answers without a true understanding of concepts.
