Question

Which of the following pair of minerals play an important role in maintaining acid-base balance?

• A. Sodium and Potassium
• B. Calcium and Phosphorous
• C. Magnesium and Calcium
• D. Iron and Copper

Hint:

Remember the transcellular exchange:
Acidosis leads to Hyperkalemia because $H^{+}$ moves into cells, forcing $K^{+}$ out into the bloodstream.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Maintaining systemic pH within a narrow range (35 to 45 in blood) is critical for protein structure and enzyme function.
The body regulates pH using chemical buffer systems, respiratory ventilation, and renal excretion of electrolytes.

Step 2: Detailed Explanation:
Sodium ($Na^{+}$) and Potassium ($K^{+}$) are the major electrolytes in the extracellular and intracellular fluids, respectively.
They are essential for maintaining osmotic pressure, water distribution, and acid-base balance:
Sodium: As the primary extracellular cation, sodium is co-transported with bicarbonate ($HCO_{3}^{-}$) and exchanged for hydrogen ions ($H^{+}$) in the renal tubules via $Na^{+}/H^{+}$ exchangers. This renal exchange directly regulates blood pH.
Potassium: Potassium ions participate in transcellular shifting during acid-base disturbances. In states of acidosis, excess extracellular hydrogen ions ($H^{+}$) enter cells in exchange for intracellular potassium ions ($K^{+}$) moving out. This buffering mechanism helps stabilize extracellular pH.
Calcium, phosphorus, and magnesium are involved in bone structure and intracellular signaling, while iron and copper function as transition metal cofactors in redox reactions.

Step 3: Final Answer:
Sodium and potassium are the primary minerals responsible for maintaining systemic acid-base and fluid balance.