Q: Which of the following best describes the role of buffers in the human body?

Buffers maintain pH by regulating changes in H\textsuperscript{+} concentration.

Question 1

Which of the following equations correctly represents the synthesis reaction used by the kidney to remove excess acid (H	extsuperscript{+}) from the body?

Accepted Answer

$\mathrm{NH_3 + H^+ \rightarrow NH_4^+}$

Question 2

A patient presents with a blood pH of 7.28. Based on the physiological pH range for humans, which condition does this patient most likely have?

Accepted Answer

Acidosis

Question 3

Which of the following best describes the role of buffers in the human body?

Accepted Answer

Buffers maintain pH by regulating changes in H	extsuperscript{+} concentration.

Question 4

Given the equation $\mathrm{CO_2 + H_2O \leftrightarrow H_2CO_3 \leftrightarrow H^+ + HCO_3^-}$, what would happen to blood pH if CO	extsubscript{2} levels increase due to hypoventilation?

Accepted Answer

Blood pH would decrease, causing acidosis.

Question 5

Which of the following statements about the pH scale is correct?

Accepted Answer

A pH less than 7 is acidic.

Question 6

If a person’s blood pH is measured at 7.50, which of the following best describes their condition?

Accepted Answer

Alkalosis

Question 7

Which chemical reaction is part of the carbonic acid-bicarbonate buffer system in the blood?

Accepted Answer

$\mathrm{CO_2 + H_2O \leftrightarrow H_2CO_3}$

Question 8

A buffer system in the blood helps maintain pH by which of the following mechanisms?

Accepted Answer

By converting strong acids into weak acids

Question 9

Which of the following is a correct interpretation of the normal physiological pH range for human blood?

Accepted Answer

7.35–7.45

Question 10

A patient with chronic kidney disease is unable to efficiently remove excess H	extsuperscript{+} ions. Which reaction is most likely impaired?

Accepted Answer

$\mathrm{NH_3 + H^+ \rightarrow NH_4^+}$

Question 11

If the blood pH drops below 7.35, which of the following buffer systems is most likely to be activated to restore homeostasis?

Accepted Answer

Carbonic acid-bicarbonate buffer system

Question 12

Which of the following best explains why the pH of blood must be tightly regulated?

Accepted Answer

Enzyme activity is highly sensitive to pH changes.

Question 13

A person is experiencing respiratory acidosis. Which chemical equation best represents the buffer system’s response?

Accepted Answer

$\mathrm{CO_2 + H_2O \rightarrow H_2CO_3 \rightarrow H^+ + HCO_3^-}$

Question 14

Which of the following would most likely result in alkalosis in a human?

Accepted Answer

Blood pH above 7.45

Question 15

If a buffer system fails in the blood, what is the most immediate consequence?

Accepted Answer

Rapid changes in blood pH

Question 16

Which of the following reactions helps neutralize excess acid in the kidney?

Accepted Answer

$\mathrm{NH_3 + H^+ \rightarrow NH_4^+}$

Question 17

Which of the following is NOT a function of the carbonic acid-bicarbonate buffer system?

Accepted Answer

Increasing blood glucose levels

Question 18

A patient with metabolic alkalosis would have which of the following blood pH values?

Accepted Answer

7.50

Question 19

Which of the following best describes the relationship between H	extsuperscript{+} concentration and pH?

Accepted Answer

As H	extsuperscript{+} concentration increases, pH decreases.

Question 20

Which of the following equations shows the reversible nature of the carbonic acid-bicarbonate buffer system?

Accepted Answer

$\mathrm{CO_2 + H_2O \leftrightarrow H_2CO_3 \leftrightarrow H^+ + HCO_3^-}$

Acid-Base Balance and pH Regulation in Human Physiology

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