Question 1

Which enzyme catalyzes the reversible hydration of CO$$_2 in $$red blood cells, playing a vital role in CO$$_2$$ transport and elimination?

Accepted Answer

Carbonic anhydrase

Question 2

What is the primary form in which CO$$_2 is $$transported in the blood from tissues to the lungs?

Accepted Answer

As HCO$$_3^- ($$bicarbonate ion)

Question 3

The Bohr effect describes how an increase in CO$$_2$$ and H$$^+$$ concentration in tissues leads to which of the following?

Accepted Answer

Decreased affinity of hemoglobin for oxygen

Question 4

Which of the following best explains why the pH of blood only drops slightly (about 0.03 units) as it passes through tissue capillaries, despite the increase in PCO$$_2$$?

Accepted Answer

Buffering action of hemoglobin and plasma proteins

Question 5

What is the physiological significance of the chloride shift in red blood cells?

Accepted Answer

It maintains electrostatic neutrality as HCO$$_3^-$$ leaves the red blood cell

Question 6

Which of the following equations correctly represents the reversible reaction catalyzed by carbonic anhydrase in red blood cells?

Accepted Answer

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

Question 7

A rightward shift in the oxygen-hemoglobin dissociation curve is caused by which of the following conditions?

Accepted Answer

Increased CO$$_2$$, increased temperature, or decreased pH

Question 8

Which of the following statements about the binding of oxygen to hemoglobin is correct?

Accepted Answer

Oxygen binds to the iron atom in the heme group at the sixth coordination site

Question 9

What is the effect of a decrease in blood pH on the oxygen-hemoglobin dissociation curve?

Accepted Answer

It shifts the curve to the right, decreasing oxygen affinity

Question 10

Which of the following best describes the role of hemoglobin in buffering blood pH?

Accepted Answer

Hemoglobin binds H$$^+$$ ions generated from carbonic acid dissociation

Question 11

Which of the following is a direct consequence of the Bohr effect in actively metabolizing tissues?

Accepted Answer

Facilitated release of oxygen from hemoglobin

Question 12

In the lungs, which process is functionally reversed compared to the peripheral tissues?

Accepted Answer

Conversion of HCO$$_3^- to CO$_2$$

Question 13

Which of the following best explains why oxygen diffuses from blood into tissues?

Accepted Answer

The PO$$_2 in $$blood is higher than in tissue cells

Question 14

What is the effect of increased temperature on the oxygen-hemoglobin dissociation curve?

Accepted Answer

It shifts the curve to the right

Question 15

Which of the following is a minor pathway for CO$$_2$$ transport in the blood?

Accepted Answer

As dissolved CO$$_2$$

Question 16

Which of the following statements about the chloride shift is correct?

Accepted Answer

It involves the influx of Cl$$^-$$ into red blood cells as HCO$$_3^-$$ exits

Question 17

Which of the following best describes the fate of HCO$$_3^- in $$the lungs?

Accepted Answer

It is converted back to CO$$_2$$ and exhaled

Question 18

Which of the following is true regarding the oxygen-hemoglobin dissociation curve in arterial versus venous blood?

Accepted Answer

Arterial blood has nearly all hemoglobin binding sites occupied by O$$_2$$

Question 19

Which of the following best describes the effect of carbaminohemoglobin formation on oxygen transport?

Accepted Answer

It decreases the affinity of hemoglobin for oxygen

Buffer Systems in Blood and Hemoglobin Function: Biochemistry Study Notes

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