pH regulation of the stomach

Nature of science:

Collecting data through sampling and trialling—one of the symptoms of dyspepsia is the overproduction of stomach acid. Medical treatment of this condition often includes the prescription of antacids to instantly neutralize the acid, or H2-receptor antagonists or proton pump inhibitors which prevent the production of stomach acid. (2.8)

• Non-specific reactions, such as the use of antacids, are those that work to reduce the excess stomach acid.
• Active metabolites are the active forms of a drug after it has been processed by the body.

Applications and skills:

• Explanation of how excess acidity in the stomach can be reduced by the use of different bases.
• Construction and balancing of equations for neutralization reactions and the stoichiometric application of these equations.
• Solving buffer problems using the Henderson–Hasselbalch equation.
• Explanation of how compounds such as ranitidine (Zantac) can be used to inhibit stomach acid production.
• Explanation of how compounds like omeprazole (Prilosec) and esomeprazole (Nexium) can be used to suppress acid secretion in the stomach.

Guidance:

• Antacid compounds should include calcium hydroxide, magnesium hydroxide, aluminium hydroxide, sodium carbonate and sodium bicarbonate.
• Structures for ranitidine and esomeprazole can be found in the data booklet in section 37.

• Different cultures (ie diet, lifestyle, etc) and genetics can affect the need for pH regulation of the stomach

. Theory of knowledge:

• Sometimes we utilize different approaches to solve the same problem. How do we decide between competing evidence and approaches?

Utilization:

• Syllabus and cross-curricular links:
• Topic 1.3—calculations involving solutions
• Topics 8.2 and 8.4—neutralization
• Topic 10.2—functional groups Topic
• 20.3—enantiomers
• Option B.7—amino acid buffers
• Biology option D.1—digestion

Aims:

• Aim 6: Experiments could include titrations to test the effectiveness of various antacids.