DP Chemistry (first assessment 2025)
Question 23M.2.HL.TZ2.20
Date | May 2023 | Marks available | [Maximum mark: 2] | Reference code | 23M.2.HL.TZ2.20 |
Level | HL | Paper | 2 | Time zone | TZ2 |
Command term | Suggest | Question number | 20 | Adapted from | N/A |
20.
[Maximum mark: 2]
23M.2.HL.TZ2.20
Suggest two reasons why the penicillin side-chain is modified.
[2]
Markscheme
bacterial resistance «to older penicillin’s/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 penicillin” for M2.
Award [1 max] for "increased efficiency/bioavailability"
OR
"increased stability in GIT".
Do not accept "bacterial tolerance".
