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NBDE PART 1 BIOCHEM/PHYSIOLOGY > Blood > Flashcards

Flashcards in Blood Deck (92):
1

normal range for hemoglobin is different b/w men and women. for men it is _ and for women it is_

men 13-18g/dl (grams per deciliter)
women is 12-16

to remember just remember that girls go thru puberty first so the number is lower, they start around 12 and end sooner too. men start later and go longer.

2

Hb is a quaternary protein with 4 __ polypeptide chains

tertiary (2 alpha and 2 beta)

3

each of the four chains in Hb has an iron containing _ group

heme

4

oxygen can bind to the _ in hemoglobin

heme group's iron will bind oxygen

5

carbon dioxide can bind to _ in hemoglobin

the amino acids in the chains

6

how many iron atoms in each Hb

4

7

each iron can bind how many oxygen molecules? how many oxygen atoms?

Hb has 4 iron's (one per heme per chain), and each iron can bind one MOLECULE of oxygen = O2, which means it can bind 2 oxygens per iron = 8 total atoms of oxygen or 4 molecules of oxygen

8

what is the normal value of Hb in women? men? newborn?
in g/dl

12-16 grams per deciliter = women
13-18 g/dl = men
14-20 g/dl in newborn

9

how do you convert dl to mL?

1 dl = 100 mL
1 dl = (10)-1
1mL = (10)-3
difference is (10)2 = 100

10

blood hemoglobin depends on the

number of rbc and amount of hb in each rbc

11

a low Hb value is found in

anemia, hyperPT and cirrhosis of liver

12

a high Hb value is found in

polycythemia, COPD, and congestive heart failure

13

the Bohr effect is very strong in the

fetus

14

blood leaving the lungs is __% saturated with oxygen

98%

15

hemoglobin of normal venous blood returning to the lungs is _ saturated

75%

16

carbaminohemoglobin is Hb that is carrying

CO2 from tissues to the lungs

17

most CO2 is transported to lungs by Hb or bicarb?

bicarbonate > 30% by carbaminohemoglobin > CO2

18

colloid osmotic pressure is

oncotic pressure (exerted by proteins in the BV)

19

___ (or tissue fluid) is a solution that bathes and surrounds the cells. It is the main component of the extracellular fluid, which also includes plasma and transcellular fluid.

Interstitial fluid

20

plasma -fibrinogen =

serum

21

plasma makes up _% of blood

55%
to remember think 55inch plasma tv

22

hematocrit makes up _% of blood

45% = formed elements/hematocrit (RBC, WBC, platelets/thrombocytes)

to remember: H looks like 4 in 45%

23

blood makes us _% of our body weight

8%
to remember: B in blood looks like an 8

24

Blood = plasma + formed elements
Plasma is the fluid portion and contains no

cells

25

serum is clear, thin, sticky part of blood that remains after you take out the fibrin from plasma. it also contains no

cells

26

proteins make up _% of plasma

7%

27

water make up _% of plasma

91%

28

other solutes make up _% of plasma

2% (hormones, metabolic products, gases, hormones, ions

29

iron is absorbed mainly in the

duodenum

30

iron is absorbed as Fe2+/Fe3+

Fe2+ duodenum

31

our bodies contain 4-5g of iron which is almost exclusively in _ form

protein bound

32

75% of iron is found in

heme = in myoglobin and hemoglobin

33

15-25% of iron is stored in the

liver, spleen bone marrow in iron protein complexes intracellularly

34

iron is stored in the form of

ferritin and hemosiderin

35

_ is a complex of ferritin, denatured ferritin, and other proteins

hemosiderin

36

after iron is absorbed into the duodenum, it combines with a beta globulin, ____ to form _

apotransferrin ==> forms transferrin

37

hemochromatosis

iron storage disease that results in the deposition of iron pigments in peripheral tissues with bronzing of skin, diabetes, and weakness

38

Hemoglobin has 2 conformational states

T (tense) and R relaxed

39

which state of hemoglobin has a weak affinity for oxygen

T = in capillaries
R= relaxed = higher affinity for oxygen in the pulmonary capillaries

40

the P50 = partial pressure of oxygen that results in 50% of Hb being saturated in normal adults

27mmHg

P50 indicates the partial pressure of a gas required to achieve 50% enzyme saturation = 2 of the 4 heme groups have O2 bound

41

the adult hemoglobin = globin (protein portion) is made of 4 polypeptide chains = ?

2 alpha and 2 beta

42

the fetal hemoglobin = globin (protein portion) is made of 4 polypeptide chains = ?

2 alpha and 2 gamma chains!

to remember = baby says gaga = 2 alpha 2 gamma

43

how many heme molecules in Hb? are these proteins?

4 heme (just like there are 4 protein/globin chains) but heme is the NON PROTEIN part

44

each heme is a nitrogen containing organic pigment that has a single iron in what state?

reduced state (Fe2+) = FERROUS iron

45

what is ferric iron?

3+

46

ferrous iron?

2+ (think two people can ride the ferrous wheel) = Hb

47

the PROTEIN PORTION of Hb will bind

carbon dioxide

48

the protein/non protein portion of Hb binds oxygen

non protein portion (Heme)

49

does carbon dioxide compete with oxygen for binding sites in Hb

No! they bind different areas. BUT CARBON MONOXIDE competes with Oxygen for spots

50

carbon monoxide has a much__affinity for Hb than oxygen

higher 240x

51

Methemoglobin contains iron in the _ state and cannot function as an oxygen carrier

ferric (3+)

52

which is less acidic deoxygenated/oxygenated hemoglobin

deoxygenated = ideal for buffering the H+ coming from tissue

53

Hb is a major _

H+ buffer

54

the most common form of Hb in adult is

HgA

55

Hemoglobin H is abnormal hemoglobin that is composed of __ chains

4 beta chains

56

Hemoglobin H is usually associated w a defect in three of the 4 alpha chain genes resulting in

alpha thalassemia

57

__ is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin, the protein in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia

Thalassemia

58

Hemoglobin is made of two proteins: Alpha globin and beta globin. Thalassemia occurs when there is a defect in a gene that helps control production of one of these proteins.

There are two main types of thalassemia:
1. Alpha thalassemia occurs when a gene or genes related to the ___ globin protein are missing or changed (mutated).
2. Beta thalassemia occurs when similar gene defects affect production of the __globin protein

1. alpha
2. beta

59

Hemoglobin _ is an abnormal hemoglobin in which valine has replaced glutamic acid in the _ chain

S, beta chain

to remember think sickle sex, chromosome Six, occurs in Blacks, Beta chain

60

Hemoglobin S is the predominant form of Hgb in pp with

sickle cell anemia

61

a major effect of sickle cell anemia is the decreased __ of the deoxy from of Hgb

solubility

62

Hemoglobin __ is a group of abnormal hemoglobins in which a single amino acid substitution favors the formation of methemoglobin and is thus associated with methemoglobinemia.

M

63

Hemoglobin _ is abnormal hemoglobin in which LYSINE has replaced GLUTAMIC ACID, causing reduced plasticity of RBCs

C

substitution of a glutamic acid residue with a lysine residue at the 6th position of the β-globin chain has occurred

64

1. when lysine replaces glutamic acid = Hb _
2. when valine replaces glutamic acid = Hb _
3. when there are 4 beta chains instead of the normal 2 alpha and 2 beta?
4. when methemoglobin formation is favored =

1. HgC
2. HgS
3. HgH
4. HgM

65

90% of all erythropoietin is formed in the _ and the rest formed in the _

90% kidneys
10% liver

66

anoxia

low oxygen: The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen

67

RBC's are _ shaped

biconcave

68

do RBC have nuclei or mitochondria

no mature RBCs do not

69

carbonic anhydrase is found in RBC it converts

CO2 and water ==> bicarb and H+

70

principal function of Rbc

carry Hg

71

portion of RBC in blood is called

hematocrit

72

do men or women have more hematocrit

men 46%
women 41%

73

life span of erythrocytes

105-120 days

74

In the early embryo, where are RBCs produced

yolk sac

75

in mid gestation where are RBC produced

mostly liver, but also spleen and lymph nodes

76

in the final month of gestation until 20years old where are RBC produced

ONLY in the bone marrow

77

after 20 years old where are RBC produced

marrow of membranous bones ie. vertebrae, sternum, ribs, ilia

78

1. _ effect states hemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide
2. _ effect states that Deoxygenation of the blood increases its ability to carry carbon dioxide; this property is the Haldane effect. Conversely, oxygenated blood has a reduced capacity for carbon dioxide

1. Bohr
2. Haldane effect

79

does myoglobin also show the Bohr effect?

The Bohr effect is dependent on allosteric interactions between the hemes of the hemoglobin tetramer. This is evidenced by the fact that myoglobin, a monomer with no allostery, does not exhibit the Bohr effect. Hemoglobin mutants with weaker allostery may exhibit a reduced Bohr effect

80

1. The iron in hemoglobin is in the reduced or oxidized state?
2. is it in ferrous or ferric state?
3. hemoglobin molecules have 4 polypeptide chains that contain _ groups.
4. the sulfhydryl groups (-SH) must be kept in reduced/oxidized form

1. reduced
2. ferrous (Fe2+)
3. sulfhydryl (SH)
4. reduced

81

transport of oxygen n the blood can occur in what 2 ways

either dissolved in plasma (outside of the RBCs) = 1.5%

or bound to hemoglobin (Hb) inside the RBC = 98.5%

82

RBCs transport both

oxygen and carbon dioxide

83

Hemoglobin in RBCs transport _% of the total amount of CO2 produced by the body as carbaminohemoglobin aka carboxyhemoglobin

30%

84

according to the hemoglobin-oxygen dissociation curve, at PO2 of 100mmHg (ex. arterial blood oxygen partial pressure) hemoglobin is _ saturated =

98% = means O2 is bound to all 4 groups on all hemoglobin molecules.

85

according to the hemoglobin-oxygen dissociation curve, at PO2 of 40mmHg (ex. mixed venous blood oxygen partial pressure) hemoglobin is _ saturated =

75% saturated = means that on average, 3 of the 4 heme groups on hemoglobin are bound

86

1. at PO2 100mmHg (arterial)= _% saturation of Hb
2. at PO2 40mmHg (venous) = _% saturation of Hb
3. at PO2 25mmHg = _% saturation of Hb

1. 98%--->all 4 heme occupied w/O2
2. 75% 3 of 4 occupied
3. 50% 2 of 4 occupied = aka the P50 point

87

__ is an iron-storage complex. It is always found within cells (as opposed to circulating in blood) and appears to be a complex of ferritin, denatured ferritin and other material

Hemosiderin

88

hemosiderin pathological relationship?

Hemosiderin is most commonly found in macrophages and is especially abundant in situations following hemorrhage, suggesting that its formation may be related to phagocytosis of red blood cells and hemoglobin.Hemosiderin often forms after bleeding (hemorrhage). When blood leaves a ruptured blood vessel, the red blood cell dies, and the hemoglobin of the cell is released into the extracellular space. Phagocytic cells (of the reticulo-endothelial system)called macrophages engulf (phagocytose) the hemoglobin to degrade it, producing hemosiderin and biliverdin. Excessive systemic accumulations of hemosiderin may occur in macrophages in the liver, lungs, spleen, kidneys, lymph nodes, and bone marrow. These accumulations may be caused by excessive red blood cell destruction (haemolysis),

89

why is hemoglobin a great buffer? what component in its structure

Histidine residues in hemoglobin can accept protons and act as buffers. Deoxygenated hemoglobin is a better proton acceptor than the oxygenated form

90

alpha thalassemia is associated with Hemoglobin H and what disease?

The worldwide distribution of inherited alpha-thalassemia corresponds to areas of malaria exposure, suggesting a protective role for alpha-thalassemia against the more severe manifestations of malaria. to remember: look at alpha (alpha chains not made) and tHalassemia = think H hemoglobin

91

Alpha-thalassemia is due to impaired production of 1,2,3, or 4 alpha globin chains, leading to a relative excess of __globin chains

beta

92

Hemoglobinopathy

a kind of genetic defect that results in abnormal structure of one of the globin chains of the hemoglobin molecule
ex. sickle cell