Acid-base homeostasis · USMLE Step 1

Which intracellular buffer system contributes significantly to pH regulation inside cells?

  1. Bicarbonate buffer system
  2. Hemoglobin buffer system
  3. Phosphate and protein buffers
  4. Ammonia buffer system
Show answer and explanation

Correct answer: Phosphate and protein buffers

Inside cells, phosphate and proteins (with ionizable side chains) serve as major intracellular buffers to resist changes in intracellular H⁺ concentration.

Difficulty: Medium Question 15 of 19

Practice all 19 Acid-base homeostasis questions

Keep practicing

More Acid-base homeostasis questions