hemoglobin Flashcards
iron bearing protein contained
within the erythrocytes
hemoglobin
one gram of hemoglobin can carry
1.34 ml of oxygen
FUNCTIONS OF
HEMOGLOBIN
Transport oxygen from the lungs
to the tissue and carbon dioxide
from the tissue
- acid- base balance regulation
1 heme is equal to
1 moles of oxygen
1 hemoglobin is equal to
4 moles of oxygen
young erythroblast is synthesized from
polychromatophilic normoblast stage up to reticulocytes stage
Structure of Heme/composition of heme
- Protophorphyrin IX
- Ferrous iron
Each globin consists of what?
8 helices separated by 7 non helices segments
2nd helix of amino acid
amino acid sequence
Secondary helix
helices and non
helices
Tertiary helix
pretzel like
configuration
quaternary helix
complete molecule
ability of hemoglobin to bind or
release oxygen . Expressed in terms of the oxygen
tension at which hgb is 50% saturated
oxygen affinity
oxygen tension also known as partial pressure
partial pressure of oxygen
relationship of O2 affinity with
Hb to pH
bohr effect
Inc Hb affinity for O2
increased pH (alkalosis)
dec hb affinity for O2
decreased pH (acidosis)
the normal position of curve depends on
§ Concentration of 2,3-DPG
§ H+ ion concentration (pH)
§ CO2 in red blood cells
§ Structure of Hb
Right shift (decreases oxygen affinity , more 02 release to the
tissues
§ High 2,3-DPG
§ Dec body pH
§ High CO2
§ HbS
hemoglobin in combination with
oxygen.
gives pinkness to the skin and mucous membrane.
seen in arterial circulation
Oxyhemoglobin
hgb with iron but no O2 seen in
venous circulation
unassociated with oxygen.
Deoxyhemoglobin
Found in normal human embryos
and fetuses with a gestational age
of less than three months
Embryonic Hemoglobin
Composed of 2 zeta and 2 epsilon globin
chains
Hemoglobin Gower I
Composed of 2 alpha and 2 epsilon
Hemoglobin Gower 2
composed of 2 zeta and 2 gamma
Hemoglobin Portland
Composed 0f 2 alpha and 2 gamma
Fetal Hemoglobin
normal adult hemoglobin
hemoglobin A or A1
the major hemoglobin of the fetus
and newborns
fetal hemoglobin
Constitutes less than 3% of the total
hemoglobin
hemoglobin A2
degradation product of HbA2
hemoglobin A3
this is the primary hemoglobin
in people with sickle cell disease
hemoglobin S
replaced by valine in the
6th position of beta chain
Glutamic acid
one of the most common beta
chain hemoglobin variants in the world
hemoglobin E
an abnormal hemoglobin that occurs in some cases of
alpha thalassemia
hemoglobin hct
Has a brownish to bluish color and does not revert to
red on exposure to oxygen.
methemoglobin
Formed by the irreversible oxidation of Hb of certain drugs and
chemicals.
sulfhemoglobin
examples of sulfhemoglobin
a. sulfonomides
b. phenacetin
c. acetanilide
silent killer for its
colorless gas , odor and patient becomes easily
hypoxic
CARBOXYHEMOGLOBIN
qualitative screening test based on
specific gravity. The density of the
drop of blood is directly proportional to
the amount of hemoglobin it contains.
Copper Sulfate Specific Gravity
principle of Copper Sulfate Specific Gravity
when
the drop of donor’s blood dropped into
copper sulfate solution becomes
encased in a sac of copper
proteinate
ref range for male
3.5-18 g/dL
ref range for femle
2-15 g/dL
NTERFERING FACTORS
Hb is normally dec during
pregnancy
People living at high altitudes have
increased Hb values, as well as inc.
Hct and RBC.
* Excessive fluid intake cause a
decreased Hb.
* Normally , the Hb is higher in infants
* Drugs
