Regulating acid-base balance

What enzyme accelerates the bicarbonate buffer reaction in red blood cells?

Carbonic Anhydrase (CA)

What does an increase in CO₂ cause in terms of acid-base balance?

Shifts equilibrium to the right → increases H⁺ → lowers pH → respiratory acidosis

What does an increase in H⁺ cause in terms of acid-base balance?

Shifts equilibrium to the left → decreases H⁺ by producing CO₂ → respiratory compensation

What happens in respiratory acidosis?

CO₂ retention due to hypoventilation or obstructive lung disease (e.g., COPD)

What is respiratory alkalosis and what causes it?

Excessive CO₂ loss due to hyperventilation

What is the role of chemoreceptors in respiratory compensation?

Detect pH/PCO₂ changes and alter breathing rate/depth

How do kidneys compensate for acid-base imbalances?

By secreting H⁺ and reabsorbing HCO₃⁻

What transporter in the kidney helps remove H⁺ and reabsorb Na⁺?

Na⁺/H⁺ exchanger (NHE)

What happens to glutamine in renal compensation?

Metabolized to HCO₃⁻ and NH₄⁺, which is excreted

What is metabolic acidosis and a common cause?

Excess H⁺ or acid accumulation (e.g., lactic acidosis from exercise)

What is metabolic alkalosis and a common cause?

Excess H⁺ loss (e.g., vomiting); kidneys may compensate by decreasing HCO₃⁻ reabsorption

How does the body respond to metabolic alkalosis?

By hypoventilation → increases CO₂ → lowers pH back toward normal

What is the dual mechanism in bicarbonate buffering?

CO₂ removal by lungs and H⁺ secretion by kidneys