Lecture 1 - Biochemical Buffers and Regulation of pH

Q: What is the normal pH range of blood?

A: 7.35–7.45 (slightly basic).

Q: What is acidosis and alkalosis?

A: Acidosis: pH < 7.35; Alkalosis: pH > 7.45.

Q: Which systems regulate metabolic and respiratory pH imbalances?

A: Metabolic: kidneys; Respiratory: lungs and CO₂.

Q: What does Ka measure?

A: The strength of an acid (its dissociation constant).

Q: How are pKa and acid strength related?

A: Lower pKa = stronger acid; higher pKa = weaker acid.

Q: What is a buffer?

A: A solution of weak acid and conjugate base that resists pH change.

Q: Why must blood pH stay within a narrow range?

A: To ensure proper enzyme and protein function.

Q: Which enzymes function best in acidic environments?

A: Stomach and lysosomal enzymes.

Q: Why is the body more prone to acidosis than alkalosis?

A: Because metabolism produces more acids than bases.

Q: What two organs regulate blood pH?

A: Lungs and kidneys.

Q: Name three acids from metabolism.

A: Lactic acid, CO2, stomach acid (HCl).

Q: How does increasing bicarbonate affect pH?

Q2: How does increasing CO₂ affect pH?

A: It raises pH (more basic).

A2: It lowers pH (more acidic).

Q: What are the four types of pH imbalance?

A: Respiratory/metabolic acidosis and alkalosis.

Q: What causes respiratory acidosis?

Q2: What causes respiratory alkalosis?

A: when the body cannot adequately eliminate carbon dioxide (CO2), leading to an increase in blood acidity. hypoventilation

A2: primarily caused by hyperventilation, which is a rapid and deep breathing that leads to excessive removal of carbon dioxide (CO2) from the body

Q: What causes metabolic acidosis?

Q2: What causes metabolic alkalosis?

A: HCO₃⁻ loss or acid retention (e.g., diarrhea, DKA).

A2: Acid loss or excess HCO₃⁻ (e.g., vomiting, antacids).

Q: How do kidneys compensate for respiratory acidosis?

A: Retain HCO₃⁻ and excrete H⁺.

Q: How do lungs compensate for metabolic acidosis?

A: Increase breathing to expel CO₂.

Q: What are signs of partial compensation?

Q2: What are signs of full compensation?

A: Secondary value out of range, but pH still abnormal.

A2: Secondary value out of range, pH back in range.