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61

Give the minimal osmotic resistance of RBCs

70-120 mmol/l NaCl

haemolysis just starts

62

Give the maximum osmotic resistance of RBCs

50 - 90 mmol/l NaCl

all the cells haemolyse

63

Osmotic resistance of the RBC is attributed to...

  • The characteristics of the RBC membrane
    • Spectrin protein molecules
      • Fixed in place by ankyrine
    • Give a flexible feature 'molecular springs'
    • On the internal side of the membrane

64

Which physical effects can cause membrane haemolysis?

  • Freezing
  • Dissolving
  • Shaking
  • Shocking
  • Osmosis

65

Which chemical effects can cause membrane haemolysis?

  • Acids
  • Liposolvents (E.g Ether, Chloroform)
  • Surface tension reducers (Bile salts)

66

Which toxins can cause membrane haemolysis?

  • Bacterial toxins
  • Snake toxins
  • Plant toxins

67

Haemoglobin

  • Pigment (protein)
  • Colours the RBCs
  • Transports blood gases
  • Forms the blood's buffer capacity

68

Give the molecular weight of Haemoglobin

65,000 Da

4 sub units

120-180 g/lblood = 1.5 - 2.5 mmol/l

69

Haem/Hem

  • Ferro-protoporphyrine
  • Porphyrine base with 4 coordination sites
  • Only the bivalent iron atom can bind to oxygen reversibly
  • (Oxygenation)

70

Methaemoglobin

  • Oxygenated derivative
  • Binds to oxygen irreversibly
  • Returned to the haemoglobin in the:
  • Methaemoglobin-reductase-NADPH-systen

71

Fe2+ prefixes

  • HEM
  • Ferro-
  • Hemo-

72

Fe3+ prefixes

  • Hemin
  • Ferri-
  • Hemi-

73

Globin

  • Determines characteristics of oxygen binding
  • Allows allosteric stimulation
  • Binds to oxygen stronger after accepting the former one

74

Describe the evolution of blood cell genetics

  • Originally one genetic chain (until 500 million years ago)
  • Became alpha and beta chains
  • 120 million years ago, beta chain spit into gamma1 and gamma2
  • Beta1, beta2 and the epsylong chains also appeared through mutation

75

Sickle-cell anaemia

  • Single amino acid change
  • The 6th position of the beta chain should contain alanine
  • It contains glutamine instead

76

Give the known Asian vector of malaria

Iwi bird

77

The age effect on RBCs

  • Hb-F has a smaller affinity to 2,3-DPG
  • (From cell metabolism, allows oxygen transport from mother to fetus)
  • When compared with Hb-A due to the amino acid sequence

78

Adult haemoglobin

Hb-A = 2 alpha chains + 2 beta chains

79

Foetal haemoglobin

Hb-F = 2 alpha chains + 2 gamma chains

80

Oxygen in RBCs

  • Bind to Fe2+ (reversible)
  • 1 haem binds to 1 O2
  • 1.34mlO2/ Hb
  • 160mlO2/l blood
  • 16% Volume

81

Carbon dioxide in RBCs

  • Carbamino-hemoglobin
    • Responsible for 20% CO2​ transport
    • Hb-NH+ CO2 → Hb-N-COOH

82

Peak absorbance wavelengths for:

  • HbO2
  • Hb

  • HbO2: 540nm, 580nm
  • Hb: 555nm

83

Haemoglobin composition: Fe2+ 

Deoxi-Hb

84

Haemoglobin composition: Fe2+ O2

Oxygenated-Hb

85

Haemoglobin composition: Fe2+ CO

CO-Hb

86

Haemoglobin composition: Fe3+ 

Hemiglobin (Methaemoglobin)

87

Haemoglobin composition: Fe3+ Cl

Hemin chloride

88

Compare the affinity of carbon monoxide to oxygen

Carbon monoxide has 200 times greater affinity than oxygen

89

Haemoglobin can be irreversibly oxidised by...

OH and Cl radicals

90

Haemoglobin can reversibly bind to...

Oxygen