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Edexcel IAL Chemistry 14.22 Importance of biological and food buffers

Tie the context to chemistry: show which buffer species removes added H+ or holds pH steady, then connect stable pH to enzymes, organisms or food preservation.

Syllabus
First assessment 2019
Course
Chemistry YCH11
Level
A2

Exam points

  • Explain HCO3- removing added H+ in blood or cells when carbon dioxide increases.
  • Explain citrate or other food buffers maintaining pH to reduce fungal or bacterial deterioration.
  • Link stable pH to enzyme function, living systems or controlled microbial growth.

14.22—The importance of buffer solutions in biological environments: i buffers in cells and in blood (H2CO3/HCO-3) ii in foods question 1

[Maximum number: 1]

The alkaline compound tris(hydroxymethyl)aminomethane, known as Tris, is used to make a buffer for biological research.

Tris

Tris

A titration curve of Tris with chloroethanoic acid is shown.

Figure for Question 14.22—The importance of buffer solutions in biological environments: i buffers in cells and in blood (H2CO3/HCO-3) ii in foods question 1 — Edexcel A-Level Chemistry A2

Suggest a reason why buffers are so important in biological systems.

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