Which biochemical change occurs in stored blood?

Which biochemical change occurs in stored blood?

• A. Plasma K+ decreases
• B. Plasma pH decreases
• C. Hematocrit decreases
• D. Hemoglobin increases

Answer: (B)

Stored blood continues a limited glycolysis in the red cells even when refrigerated, producing lactate and hydrogen ions. The buffering systems in plasma get overwhelmed, so the plasma pH gradually falls as storage time increases. This acidification is the main biochemical change observed in stored blood. Potassium can leak out of red cells and rise in plasma over time, but that reflects electrolyte leakage rather than the acid-base shift described here. Hematocrit and hemoglobin levels aren’t the primary biochemical changes occurring with storage.

Stored blood continues a limited glycolysis in the red cells even when refrigerated, producing lactate and hydrogen ions. The buffering systems in plasma get overwhelmed, so the plasma pH gradually falls as storage time increases. This acidification is the main biochemical change observed in stored blood. Potassium can leak out of red cells and rise in plasma over time, but that reflects electrolyte leakage rather than the acid-base shift described here. Hematocrit and hemoglobin levels aren’t the primary biochemical changes occurring with storage.