DP Chemistry (last assessment 2024)
Question 18M.3.sl.TZ1.14b
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.sl.TZ1.14b |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
18M.3.sl.TZ1.14b
Excess stomach acid can be counteracted by a range of medications.
(b)
Explain how omeprazole (Prilosec) reduces stomach acidity.
[2]
Markscheme
inhibits the secretion of stomach acid/H+
«active metabolites» bind «irreversibly» to «receptors of the» proton pump
Accept “PPI/proton pump inhibitor”.
Do not award mark for “binds to H2/histamine receptors”. (Ranitidine mode of action.)
Accept “H+/K+ ATPase” for “proton pump”.
[2 marks]
