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Essential Biochemistry - Chemistry Of Hemoglobin (Section 1)

1
Which of the following is NOT a normal derivative of hemoglobin?
Answer
(D)
Methemoglobin
2
What is the effect of high altitude on the binding of oxygen to hemoglobin?
Answer
(A)
Decreases the affinity of hemoglobin for oxygen
3
How does 2,3-BPG affect the oxygen-hemoglobin binding curve?
Answer
(B)
Shifts it to the right
4
Where does the binding of oxygen to hemoglobin primarily occur?
Answer
(A)
In the heme group
5
Which of the following is a characteristic of sickle cell anemia?
Answer
(C)
The red blood cells become sickle-shaped.
6
Which of the following factors causes the 'T' (tense) state of hemoglobin?
Answer
(D)
Low pH
7
Which factor causes a rightward shift in the oxygen-hemoglobin dissociation curve?
Answer
(C)
Increased 2,3-BPG
8
Which of the following describes the Tense (T) state of hemoglobin?
Answer
(C)
Low affinity for oxygen
9
What is methemoglobin?
Answer
(B)
Hemoglobin with iron in the ferric (Fe3+) state.
10
What is the effect of CO2 on the affinity of oxygen to hemoglobin?
Answer
(B)
Decreases affinity
11
What happens in the lungs regarding oxygen and hemoglobin?
Answer
(C)
High oxygen levels, Hb binds oxygen.
12
The binding of carbon dioxide to hemoglobin forms:
Answer
(B)
Carbaminohemoglobin
13
Which of the following is a characteristic of sickle cell anemia?
Answer
(C)
The red blood cells become sickle-shaped.
14
What is the effect of carbon dioxide on the affinity of oxygen to hemoglobin?
Answer
(B)
Decreases the affinity
15
What is the role of the porphyrin ring in hemoglobin?
Answer
(B)
To bind and sequester iron
16
What is the effect of carbon monoxide on hemoglobin?
Answer
(D)
It binds to the iron atom, preventing oxygen binding.
17
What causes methemoglobinemia?
Answer
(B)
Oxidation of ferrous iron in hemoglobin
18
The globin chains are linked to the heme through:
Answer
(A)
Histidine
19
In which state does the heme iron normally exist in functional hemoglobin?
Answer
(B)
Fe2+
20
Which of the following increases the affinity of hemoglobin for oxygen?
Answer
(C)
Decreased 2,3-BPG
21
Which of the following is NOT a normal form of hemoglobin?
Answer
(C)
HbS
22
Which type of anemia is caused by the production of an abnormal hemoglobin?
Answer
(C)
Sickle cell anemia
23
What is the name for the disease caused by deficiency of hemoglobin?
Answer
(B)
Anemia
24
Hemoglobin is a:
Answer
(C)
Tetrameric protein
25
Which type of hemoglobin is found in a fetus?
Answer
(B)
HbF
26
What are the two types of thalassemia?
Answer
(A)
Alpha and beta
27
What is the name of the bond that holds the iron atom in the heme group?
Answer
(C)
Coordinate bond
28
What is the result of binding of CO2 to hemoglobin?
Answer
(B)
Carbaminohemoglobin formation
29
Which of the following statements is true regarding the binding of oxygen to hemoglobin?
Answer
(C)
Binding is increased by low 2,3-BPG levels.
30
Which of the following leads to sickle cell anemia?
Answer
(B)
Mutation of beta-globin gene
31
What is the function of the globin part of hemoglobin?
Answer
(C)
To stabilize the heme group
32
In which form is the iron atom in hemoglobin able to bind oxygen?
Answer
(B)
Fe2+ (ferrous)
33
What is the primary role of the globin chains in hemoglobin?
Answer
(B)
To stabilize the heme group
34
What does 'M' in HbM (hemoglobin M) represent?
Answer
(A)
Mutation
35
What type of bond does the iron atom form in the heme group?
Answer
(C)
Coordinate
36
Which of the following factors decreases the affinity of hemoglobin for oxygen?
Answer
A
B
C
37
What type of bonds stabilize the quaternary structure of hemoglobin?
Answer
(A)
Ionic bonds, hydrogen bonds and salt bridges
38
Which of the following is a characteristic of HbF?
Answer
(A)
Higher affinity for oxygen than HbA
39
What is the condition where the globin chain is impaired due to genetic defect?
Answer
(A)
Thalassemia
40
Prophyrin is formed by joining pyrole rings by:
Answer
(A)
Methane bridge
41
Binding of oxygen to hemoglobin is enhanced by:
Answer
(A)
increased pH and low CO2 concentration.
42
What is the effect of increasing CO2 concentration on oxygen binding?
Answer
(B)
Decreases oxygen binding
43
What is the normal percentage of HbA in adults?
Answer
(C)
Approximately 97%
44
What is the role of iron in the heme group?
Answer
(A)
To bind oxygen.
45
HbS results from a mutation in which globin chain?
Answer
(B)
Beta
46
Which factor decreases the affinity of hemoglobin for oxygen?
Answer
(C)
Increased 2,3-BPG
47
What is the primary function of the heme group?
Answer
(B)
To bind and transport oxygen
48
Normal adult hemoglobin HbA has the following chains:
Answer
(A)
α2β2
49
What is the main difference between HbA and HbF?
Answer
(A)
HbF has higher affinity for oxygen
50
What are the components of HbA?
Answer
(A)
Two alpha and two beta chains