Oxygen Dissociation Curve

Q.

Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?

Q.

Define the oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?

Q.

The partial pressure of oxygen in the lungs is

1. 60 mm Hg

2. 40 mm Hg

3. 120 mm Hg

4. 100 mm Hg

Q. Which one of the given graph shows the effect of pH on the velocity of a typical enzymatic reaction (V)?

1. 
2. 
3. 
4. 

Q.

$P_{5}0$ is the partial pressure of oxygen at which haemoglobin is 50% saturated. What will happen to the$P_{5}0$ value if there is an increase in the partial pressure of Carbon dioxide and what effect will it have on the oxygen affinity of haemoglobin (Hb)?

1. $P_{5}0$ value will decrease and the oxygen affinity of Hb will increase

2. $P_{5}0$value will increase and the oxygen affinity of Hb will increase

3. $P_{5}0$ value will decrease and the oxygen affinity of Hb will decrease

4. $P_{5}0$ value will increase and the oxygen affinity of Hb will decrease

Q.

Hamburger’s phenomenon is also called:

1. Hydrogen shift

2. Bicarbonate shift

3. Chloride shift

4. Sodium shift

Q.

Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?

Q.

Why is the oxygen dissociation curve S shaped?

Q. When partial pressure of $C{O}_2\left(pC{O}_2\right)$ rises, the oxygen dissociation curve of haemoglobin will

1. Become irregular
2. Shift towards right
3. Shift towards left
4. Remain unchanged

Q. As the partial pressure of oxygen is increased from 70 to 90, the percentage saturation of haemoglobin

1. Increases
2. Decreases
3. Remains the same
4. Increases initially but gradually decreases

Q. In the given figure curve shows percentage saturation of haemoglobin with $O_2$ is plottedagainst $p{O}_2$. This curve is highly useful instudying the effect of which factors on binding of $O_2$ with haemoglobin?

1. $pC{O}_2$
2. $H^{+}$concentration
3. Both b and c
4. Carbonic anhydrase

Q. What will be the $p{O}_2$ and $pC{O}_2$ in the atmospheric air compared to those in the alveolar air?

Q. Decrease in pH causes the oxygen dissociation curve of haemoglobin to shift to

1. left
2. right
3. remain unchanged
4. oscillate erratically

Q.

The exchange of oxygen and carbon dioxide between alveolar air and blood is governed by

1. diffusion

2. blood pressure

3. gravity

4. active transport

Q. Assertion :A sigmoid curve is obtained when percentage saturation of haemoglobin with $O_2$ is plotted against the P$O_2$. Reason: Every 100 mL of oxygenated blood can deliver around 5ml of $O_2$ to the tissues under normal physiological conditions.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. The y-axis of the oxygen-haemoglobin dissociation curve represents

1. the partial pressure of oxygen
2. the partial pressure of carbon dioxide
3. the number of haemoglobin molecules available for oxygen transport
4. the percentage of haemoglobin saturation

Q.

The oxygen dissociation curve is shifted to the right by an increase in _____

1. PCO₂

2. H+ concentration

3. temperature

4. All of these

Q. Dissociation of oxyhaemoglobin in blood increases when there is

1. increase in pH and decrease in ${\mathrm{CO}}_2$ concentration
2. decrease in temperature and increase in $O_2$ concentration
3. increase in $O_2$ concentration and decrease in ${\mathrm{CO}}_2$ concentration
4. decrease in pH and increase in ${\mathrm{CO}}_2$ concentration

Q. Given below is a sigmoid curve for oxyhemoglobin dissociation :-
Which of the following factor favour for shifting of curve (B) $\leftarrow$ (A)

1. Low $P{O}_2$, less $H^{+}$ concentration, less temperature.
2. High $P{O}_2$, less $H^{+}$ concentration, less temperature.
3. Low $P{O}_2$, less $H^{+}$ concentration, more temperature.
4. None of these

Q.

The oxygen - haemoglobin dissociation curve will show a right shift in case of

(a) high $pC{O}_2$

(b) high $p{O}_2$

(c) high $pC{O}_2$

(d) less $H^{+}$ concentration

Q. How much oxygen is delivered by $100$ ml of oxygenated blood to the tissues under normal physiological conditions?

1. $10$ ml
2. $15$ ml
3. $5$ ml
4. $2.5$ ml

Q. Dissociation curve for haemoglobin is obtained by plotting partial pressure of oxygen against percentage saturation of

1. Hb with carbon dioxide
2. Hb with oxygen
3. Carboxyhaemoglobin
4. Both A and B

Q. What would happen when blood is acidic?

1. Binding of oxygen with haemoglobin increases.
2. Red blood corpuscles are formed in higher number.
3. Binding of oxygen with haemoglobin decreases.
4. There is no change in oxygen binding nor number of RBC.

Q. The sigmoid shape of the dissociation curve is because

1. In the lungs, the partial pressure of oxygen is high
2. Tissues have a low oxygen concentration
3. The curve shows the equilibrium of oxyhaemoglobin and haemoglobin
4. Binding of oxygen to haemoglobin. As the first oxygen molecule binds to haemoglobin, it increases the affinity for the second molecule of oxygen to bind. Subsequently, haemoglobin attracts more oxygen.

Q. Which pair will be most important in initiating blood clotting?

1. Prothrombin
2. Ca and prothrombin
3. Thrombin and fibrinogen
4. Prothrombin and fibrinogen

Q.

pH of blood is

1. more in arteries, less in veins

2. less in arteries, more in veins

3. same in both

4. not definite

Q.

Oxygen associates with haemoglobin under which of the following conditions?

1. Low partial pressure of oxygen

2. A high partial pressure of carbon dioxide

3. Low H⁺ ion concentration

4. High temperature

Q.

why venous blood is red in color even though it has deoxgenated blood?

Q.

Absorption of water by living or dead tissue is called ____.

Q.

Regarding assertion and reason, choose the correct option.

Assertion [A]: Partial pressure of oxygen is an important factor affecting binding.

Reason [R]: The binding of oxygen with haemoglobin is primarily related to partial pressure.

1. Reason [R] is True and Assertion [A] is False

2. Assertion [A] is True and Reason [R] is False.

3. Assertion [A] is True and Reason [R] is True but is not a correct explanation to [A].

4. Assertion [A] is True and Reason [R] is True and is a correct explanation to [A].