Essential Biochemistry - Chemistry Of Hemoglobin (Section 4)
1
What is the effect of carbon monoxide (CO) on oxygen binding to hemoglobin?
Answer
(C)
It competes with oxygen for binding sites.
2
Which type of hemoglobin is predominantly found in the fetus?
Answer
(C)
HbF
3
Which of the following has a protective effect against malaria?
Answer
(B)
HbS
4
Porphyrin is formed by joining pyrrole rings by:
Answer
(A)
Methane bridge
5
Which factors can shift the oxygen dissociation curve to the right?
Answer
A
B
C
6
The binding sites for oxygen, hydrogen, and carbon dioxide are
Answer
A
C
D
7
Which of the following is not true for thalassaemia?
Answer
(A)
It is a δ-thalassemia
8
What is the Bohr effect?
Answer
(A)
The effect of pH and CO₂ concentration on the binding and release of O₂ by hemoglobin
9
In the context of sickle cell anemia, what does the 'sticky patch' on the HbS molecule cause?
Answer
(C)
Polymerization of HbS molecules
10
Which of the following statements is TRUE regarding fetal hemoglobin (HbF)?
Answer
(B)
HbF does not bind 2,3-BPG effectively.
11
Give cause for the sickling of RBC:
Answer
(B)
Valine is present instead of glutamic acid in Hb
12
Which condition is associated with an increased level of HbA2?
Answer
(B)
Thalassemia
13
Which of the following statement is true about the sickle cell trait?
Answer
(C)
Individuals with the trait are usually asymptomatic.
14
What is the effect of 2,3-Bisphosphoglycerate (2,3-BPG) on the oxygen-hemoglobin binding curve?
Answer
(B)
Shifts the curve to the right
15
Which factor increases the affinity of hemoglobin for oxygen?
Answer
(C)
Decreased 2,3-BPG
16
What is carboxyhemoglobin?
Answer
(C)
Hemoglobin bound to carbon monoxide
17
What is the most prevalent type of hemoglobin found in a healthy adult?
Answer
(B)
HbA
18
In which form of hemoglobin is the iron atom in the ferric (Fe³⁺) state?
Answer
(C)
Methemoglobin
19
How does the presence of CO affect the oxygen-hemoglobin dissociation curve?
Answer
(B)
Shifts the curve to the left.
20
What is the main characteristic of methemoglobinemia?
Answer
(A)
Decreased oxygen-carrying capacity.
21
Which of the following conditions is NOT directly related to hemoglobin?
Answer
(C)
Leukemia
22
In the relaxed (R) form:
Answer
A
B
23
HbF binds O₂ more tightly by even lacking:
Answer
(A)
β₂
24
Which metal atom is essential for the function of hemoglobin?
Answer
(C)
Iron
25
Give cause for the sickling of RBC:
Answer
(C)
Increased HbS
26
Which condition results from the inheritance of two copies of the β-globin gene mutation?
Answer
(B)
β-thalassemia major
27
What is the normal adult hemoglobin composed of?
Answer
(B)
Two alpha chains and two beta chains.
28
What is the effect of increased 2,3-BPG on the oxygen-hemoglobin dissociation curve?
Answer
(B)
Shift to the right
29
Which factors can shift the oxygen-hemoglobin dissociation curve to the left?
Answer
A
B
30
What is the effect of pH on the oxygen-hemoglobin binding?
Answer
(C)
Increased pH increases oxygen binding affinity.
31
What is the main function of the globin part of the hemoglobin molecule?
Answer
(C)
Protecting the heme group
32
What causes the 'sticky patch' in sickle cell hemoglobin (HbS) that leads to polymerization?
Answer
(B)
The substitution of valine for glutamic acid.
33
Hemoglobin is a:
Answer
(C)
Tetrameric protein
34
What is the primary physiological role of 2,3-BPG?
Answer
(B)
To facilitate oxygen release from hemoglobin in the tissues.
35
What is the role of histidine in the hemoglobin molecule?
Answer
(C)
To connect iron to the globin chain
36
HbF has high affinity for O₂ than HbA due to presence of:
Answer
(C)
γ chain
37
Which of the following statements are true about the effect of carbon dioxide on oxygen binding?
Answer
A
C
38
What is the role of 2,3-Bisphosphoglycerate (2,3-BPG) in the context of hemoglobin?
Answer
(B)
It decreases the affinity of hemoglobin for oxygen
39
How does carbon monoxide (CO) interfere with oxygen transport?
Answer
(B)
CO binds to the same site as oxygen in the heme group, with a higher affinity.
40
What are the different types of normal hemoglobin derivatives?
Answer
A
B
C
41
What is the term for the condition in which the iron in hemoglobin is oxidized to the ferric (Fe³⁺) state?
Answer
(B)
Methemoglobinemia
42
Which of the following statements is true regarding the Tense (T) form of hemoglobin?
Answer
(C)
It is stabilized by salt bridges, hydrogen bonds, and van der Waals forces
43
The main action consequence is that small blood capillaries in different organs become blocked by the long abnormally shaped red cell. This blocks the supply of oxygen and leads to anaemia of the tissue that causes pain and eventually death of the patient. This condition is referred as:
Answer
(A)
Sickle cell anemia
44
Which factors influence the oxygen-hemoglobin dissociation curve?
