Buffers
a “ The Henderson Hassalbalch equation is used to calculate the pH of a buffer solution. \
What our notes say
- a “ The Henderson Hassalbalch equation is used to calculate the pH of a buffer solution. \ (bchem EOY 2015 — Past Paper Questions & Answers)
- The Henderson — Hasselbalch equation is important in the calculation of a pH of a buffer q Pp solution. (bchem EOY 2014 (2) — Past Paper Questions & Answers)
- Renal compensation retains bicarbonate to buffer the acidosis; "partial" compensation means the pH remains below normal despite the raised HCO3. (Chemical path 2021 — Past Paper Questions & Answers)
- Hemoglobin acts as an important intracellular buffer: deoxygenated hemoglobin is a weaker acid than oxyhemoglobin, so it more readily binds the H⁺ generated from carbonic acid dissociation in the tissues (Haldane effect) (Chemical path 2021 — Past Paper Questions & Answers)
- The Henderson - Hasselbalch equation is important in the calculation of a pH of a buffer solution. (Biochemistry End of Year Exam — 2014 (Past Paper))
- Dukoral needs a buffer and Euvichol (a non-buffered oral vaccine) does not. (Internal Medicine CAT 1 (MBIM 6112), 2019/2020: gastroenterology and hepatology,)
Study material on Buffers
- bchem EOY 2011
- bchem EOY 2011 (2)
- bchem EOY 2014 (2)
- Chemical Pathology MCQs: Diabetes, Renal & Liver Disease
- Biochemistry End of Year Exam — 2014 (Past Paper)
- END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams
- Internal Medicine CAT 1 (MBIM 6112), 2019/2020: gastroenterology and hepatology, 30 MCQs and 4 short answers
- Chemical path 2021
- CRASH COURSE PART 3 CHEMICAL PATHO
- Polymerase Chain Reaction (PCR)
- bchem makeup cat (2) — Past Paper Questions & Answers
- Biochemistry Makeup Exam — 2020 (Past Paper)
- ACIDOSIS AND ALKALOSIS MCQs
- Weekly Pathology Exam - May 15, 2026 (Section A: MCQs)
- Weekly Pathology Exam - May 1, 2026 (Section A: MCQs)
- Weekly Pathology Exam - April 21, 2026 (Section A: MCQs)
Practice questions on Buffers
Ammonia is an effective and important urinary buffer for which of the following reasons
- Its production in the kidney decreases during chronic acidosis
- The walls of the renal tubules are impermeable to NH3
- The walls of the renal tubules are impermeable to NH4+
- Its acid base reaction has a low pKa
- None of the above
Answer: C. NH3 diffuses into tubular fluid where it combines with H+ to form NH4+. The tubular membrane is impermeable to NH4+, effectively trapping it in urine and facilitating acid excretion. ---
Which buffer system is the PRIMARY extracellular buffer system in the body?
- Protein buffer system
- Phosphate buffer system
- Bicarbonate buffer system
- Hemoglobin buffer system
Answer: C. ** The bicarbonate buffer system (H2CO3/HCO3-) is the primary extracellular buffer system, particularly in blood plasma, maintaining pH within the normal range of 7.35-7.45. ---
Which buffer system is most important in regulating intracellular pH and urine pH?
- Bicarbonate buffer system
- Protein buffer system
- Phosphate buffer system
- Ammonia buffer system
Answer: C. ** The phosphate buffer system (HPO4²-/H2PO4-) plays a significant role in buffering intracellular fluids and urine, accepting or donating hydrogen ions depending on pH. ---
Which medication is commonly used to treat severe metabolic acidosis by acting as a buffer?
- Acetazolamide
- Furosemide
- Sodium bicarbonate
- Potassium chloride
Answer: C. ** Sodium bicarbonate acts as a buffer by accepting hydrogen ions, thereby increasing blood pH in severe metabolic acidosis, though its use has potential complications. ---
Which buffer system is the PRIMARY extracellular buffer system in the body?
- Phosphate buffer system
- Proteins
- Bicarbonate buffer system
- Hemoglobin
Answer: C. The bicarbonate buffer system (CO2/H2CO3/HCO3-) is the most important extracellular buffer system due to the ability of the respiratory system to regulate CO2 and the kidneys to regulate HCO3-.
Which buffer system is the PRIMARY extracellular buffer system in the body?
- Phosphate buffer system
- Protein buffer system
- Bicarbonate-carbonic acid buffer system
- Hemoglobin buffer system
Answer: C. The bicarbonate-carbonic acid buffer system is the most important extracellular buffer, linking directly to the respiratory system (CO2 excretion) and renal system (HCO3- reabsorption/excretion).