Date | May 2018 | Marks available | 2 | Reference code | 18M.3.HL.TZ2.20 |
Level | Higher level | Paper | Paper 3 | Time zone | Time zone 2 |
Command term | Explain | Question number | 20 | Adapted from | N/A |
Question
State the disease caused by Helicobacter pylori.
Outline how gastric acid is produced in the stomach.
Explain why proton pump inhibitors alleviate the symptoms of H. pylori infections.
Markscheme
stomach ulcer
OR
stomach cancer
a. sight/smell/«presence of» food in stomach stimulates nervous system
b. nervous system/vagus nerve stimulates gastric glands «to produce gastric acid»
c. gastrin controls release of gastric acid
d. parietal cells «are stimulated to» release gastric/hydrochloric acid/HCl
e. acidity maintained by the proton pump/H+/K+ ATPase
a. as proton pumps are inhibited less protons/H+ into stomach «lumen»
b. «less protons/H+ in stomach» less hydrochloric acid produced
OR
stomach «contents» become less acidic
OWTTE.
c. stomach heals with higher pH