Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Hematology Exam 1 > Hemoglobin > Flashcards

Hemoglobin Flashcards

0
Q

What does hemoglobin do?

A

Transports O2 from the lungs to tissue

Facilitates CO2 transfer from tissue to lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What is hemoglobin?

A

A highly specialized intracellular RBC protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Hemoglobin occupies how much of the volume of RBC?

A

33%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much does hemoglobin account for RBC dry weight?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Each cell contains how how much hemoglobin?

A

28 - 34 pg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Most hemoglobin synthesis occurs in what?

A

Polychromatophilic normoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What percentage of hemoglobin is made before the nucleus is extruded?

A

75 - 80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

20 - 25% of hemoglobin was made by what?

A

Residual RNA & mitochondria in the reticulocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hemoglobin concentration is the result of a fine balance between what?

A

RBC production & destruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hemoglobin has what type of protein?

A

Globular protein 64.4 kD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How many hemoglobin are there per RBC?

A

250 million / RBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the components of the molecular hemoglobin structure?

A 
2 alpha chains
2 beta chains
Each chain has a heme
Each heme has a tetrapyrrole ring with iron (Fe2+) in the center
Each iron/heme can bind to one O
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the functions of hemoglobin?

A

Transport & release oxygen to tissues with specific conditions
Removal of CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two conformations of hemoglobin?

A

“Relaxed”Oxyhemoglobin

“Tense”Deoxyhemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does relaxed oxyhemoglobin have?

A

High affinity for O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does tense deoxyhemoglobin have?

A

Low affinity for O2

2,3-DPG (diphosphoglycerate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When hemoglobin has a high affinity for O2 what happens?

A

It binds to O2 more avidly

Does not readily release it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When hemoglobin has a low affinity for O2 what happens?

A

Releases its O2 more readily to tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does respiratory movement mean in regards to hemoglobin?

A

It has an allosteric shape with oxygen addition & release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does 2,3-DPG affect oxygen affinity?

A

It’s the primary allosteric regulator of Hb

Large amounts of 2,3-DPG changes Hb from relaxed to tense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Increased 2,3-DPG shifts O2 saturation cure to what direction?

A

Right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What type of protein is hemoglobin?

A

Allosteric protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Allosteric protein means that it does what?

A

Changes shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What molecules affect Hb?

A

Protins (H+)
CO2
2,3-DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What preferentially binds to deoxyhemoglobin?

A

2,3-DPG,
CO2
H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When 2,3-DPG , CO2, or H+ bind to deoxyhemoglobin what happens?

A

Forms salt bridges within & between chains

Stabilizes T conformation of Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

2,3-DPG binds to Hb in what ratio?

A

1:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where does 2,3-DPG bind to on hemoglobin?

A

In the central cavity of the Hb tetramer between the beta-globin chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When 2,3-DPG binds to Hb what happens?

A

Stabilizes the quarternary structure of deoxyhemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What type of interaction is O2 binding to Hb?

A

Heme-heme interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the ratio that O2 binds to H2?

A

4:1

One O2 binds to each heme group of the tetramer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Does the T conformation of deoxyhemoglobin have low or high O2 affinity?

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

When O2 is loaded onto the Hb molecule what happens?

A

Salt bridges are broken causing the molecule to go from tense to relaxed state when the third O2 is loaded
Pulls the beta-chains together & expels 2,3-DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

When O2 is released by Hb into the tissues what happens?

A

Heme pockets narrow
Restrict entry of O2
Space between the beta-chains widen
2,3-DPG binds again in the central cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Tense hemoglobin is called what?

A

Deoxyhemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

O2 affinity is usually expressed as what?

A

PO2 at which 50% of the Hb is saturated with O2 (P50)

P50 in humans ˜26-28 torr (mmHg)

36
Q

Bohr effect

A

Physiological phenomenon stating that hemoglobin’s oxygen binding affinity is inversely related both to acidity & the concentration of carbon dioxide
Increase of CO2 decreases pH -> Hb releases O2
Decrease of CO2 increases pH -> Hb picks up O2

37
Q

Increased acid shifts the oxygen dissociation curve which way?

A

Right

38
Q

Decreased acid shifts oxygen dissociation curve which way?

A

Left

39
Q

What values (high/low) of pH, DPG, temp, & P50 for a right shifted oxygen curve?

A

Low pH
High DPG
High temp
High P50

40
Q

What is P50?

A

50% of Hb is saturated with O2

41
Q

What values (high/low) of Hb, pH, DPG, temp, & P50 are a left shifted oxygen curve?

A 
High Hb
High pH
Low DPG
Low temp
Low P50
42
Q

What are the types of abnormal hemoglobin?

A

Carboxyhemoglobin
Methemoglobin
Sulfhemoglobin

43
Q

Carboxyhemoglobin is formed when?

A

Hb is exposed to CO (carbon monoxide)

44
Q

Carboxyhemoglobin results in a shift in what direction?

A

Left

45
Q

Carboxyhemoglobin results in high/low affinity & a high/ low release of O2 by what?

A

High affinity
Low release of O2
Remaining normal to Hb molecules

46
Q

What color is the blood & skin due to carboxyhemoglobin?

A

Cherry red

47
Q

What causes methemoglobin?

A

Hb with iron in the ferric (Fe+++) state

48
Q

Hb affinity for CO is 200 times higher than for O2 is?

A

Carboxyhemoglobin

49
Q

In methemoglobin Hb can or cannot bind O2?

A

Cannot

50
Q

In methemoglobin Hb has a high/low affinity of remaining normal Hb & increases/decreases O2 carrying capacity of the blood?

A

High afffinity

Decreases O2 carrying capacity

51
Q

Methemoglobin can be what three types?

A

Congenital
Hereditary
Acquired

52
Q

The blood sample can be what in color?

A

Chocolate brown

53
Q

Sulfhemoglobin is caused when?

A

A sulfur atom binds to periphery of porphyrin ring of the heme group of Hb

54
Q

Characteristics of sulfhemoglobin are?

A

Stable compound
RBC carries it until the cell is removed from circulation
Can combine with CO to form carboxysulfhemoglobin

55
Q

Sulfhemoglobin is elevated in what conditions?

A

Severe constipation

Bacteremia with Clostridium

56
Q

Sulfhemoglobin is associated with what?

A

Occupational exposure to sulfur compounds
Environmental exposure to polluted air
Exposure to certain drugs

57
Q

May build up with chronic constipation & is irreversible?

A

Sulfhemoglobin

58
Q

Patient blood has chocolate brown color?

A

Methemoglobin

59
Q

200 times the affinity for hemoglobin than oxygen, easily fatal?

A

Carboxyhemoglobin

60
Q

What will NOT shift the oxygen dissociation to the right?

A

Increased pH

61
Q

What are the steps in hemoglobin composition synthesis?

A

4 globin chains - protein synthesis
Each globin has 1 heme - heme synthesis
Each heme has 1 iron - iron transport/storage

62
Q

What is heme?

A

An iron containing non-protein portion of the hemoglobin molecule

63
Q

What is the structure of heme?

A

Ferro-protoporphyrin, a cyclical compound with 4 Pyrrhole rings* held together by nitrogen bonds holding an atom of iron in the center

64
Q

Each heme contains one atom of what?

A

Ferrous iron

65
Q

Ferrous iron has a bond that does what?

A

Reversibly binds oxygen

66
Q

Hemoglobin biosynthesis occurs where?

A

Mitochondria

67
Q

What is COPRO?

A

Coproporphyringen

68
Q

What is PROTO?

A

Protoporhpyrin

69
Q

What is the sequence of heme biosynthesis (6 parts)?

A 
ALA 
PBG - Porphobilinogen
URO - Uroporphyrinogen
COPRO - Coproporphyrinogen
Protoporphyrinogen/PROTO - Protoporphyrin IX
70
Q

Assembly of hemoglobin occurs where?

A

Mitochondria

71
Q

What hemoglobins are in adults?

A

HbA - a2b2

Alpha 2 Beta 2

72
Q

What hemoglobin are in newborns?

A

a2g2 Fetus - HbF

Alpha 2 Gamma 2

73
Q

What hemoglobins are found in small amounts in adults?

A

a2d2 - HbA2

Alpha 2 Delta 2

74
Q

What hemoglobins are found in embryos?

A

a2e2

Alpha 2 Epsilon 2

75
Q

Adult hemoglobin consists of 2 alpha and 2 ____ globins?

A

Beta

76
Q

Fetal hemoglobin consists of 2 alpha and 2 _____ globins?

A

Gamma

77
Q

What hemoglobin starts in the fetus?

A

Beta

78
Q

What hemoglobin is in the fetus?

A

Gamma

79
Q

What is the sequence of hemoglobin from embryo to birth?

A

Epsilon Gamma Beta

80
Q

What type of hemoglobin is in the embryonic stage?

A

Epsilon

81
Q

What hemoglobin is in the fetal stage?

A

Gamma

82
Q

What hemoglobin is present throughout a persons life?

A

Alpha

83
Q

What hemoglobin starts high before birth but drops after birth?

A

Gamma

84
Q

What hemoglobin starts low before birth but then goes up after birth?

A

Beta

85
Q

What is the correct order of heme synthesis?

A 
Succinyl CoA + glycine
Delta ALA
Porphobilinogen
Uroporphyrinogen
Coprophorphyrinogen
Protophorphyrinogen
Heme
86
Q

Tense hemoglobin has what?

A

2,3-DPG

87
Q

A patient with pH of 7.035 will have what effect on hemoglobin saturation?

A

Shift to the right

88
Q

What globin chain is turned on during embryonic development and stays on?

A

Alpha

Hematology Exam 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions