Hemoglobin Flashcards
to An iron bearing protein contained within the erythrocytes
Hemoglobin
The hemoglobin is synthesized by ______ and ________ stage up to reticulocytes stage
young erythroblast & polychromatophilic normoblast
a one gram of Hgb can carry how many ml of oxygen
1.34 ml
what are the composition of heme?
Protophorphyrin IX, Ferrous iron
What compose the 4 globin structure
2 identical pairs of unlike polypeptide chains, 141 to 146 amino acids each
each globin - 8 helices separated by 7 non helices segments
number of amino acids of Alpha & Zeta
141
Complete hemoglobin molecule described by?
Primary- amino acid sequence
secondary - helices and non helices
tertiary - pretzel like config.
quaternary - complete molecule
Occurs in the cytoplasm of normoblast and reticulocytes
Globin
It is manufactured in the ribosomes
polypeptide chains
It is made via transcription of m gen. code to mRNA and translation of mRNA
Globin protein
true or false: The third function of hemoglobin involves the binding, inactivation, and transport of nitric oxide.
true
It is secreted by vascular endothelial cells and causes relaxation of vascular wall smooth muscle and vasodilation
Nitric oxide
is the ability of hemoglobin to bind or release oxygen . Expressed in terms of the oxygen tension at which hgb is 50% saturated
Oxygen Affinity
true or false: The relationship between O2 tension and hemoglobin saturation with oxygen is described as ODC
true
it is a relationship of O2 affinity with Hb to pH which states that :
Inc pH ( alkalosis) = Inc Hb affinity for O2
Dec pH ( acidosis )= dec hb affinity for O2
Bohr effect
Modified true or false :
Inc pH ( alkalosis)= dec Hb affinity for O2
Dec pH ( acidosis )= inc hb affinity for O2
both false
Inc pH ( alkalosis)= Inc Hb affinity for O2
Dec pH ( acidosis )= dec hb affinity for O2
Shift to the left or shift to the right:
Decreased Temperature
Shift to the left
Shift to the left or shift to the right:
increased Organic phosphates
shift to the right
Shift to the left or shift to the right:
Increased p(CO2)
Shift to the right
Shift to the left or shift to the right:
decreased p(CO)
Shift to the right
Shift to the left or shift to the right:
increased pH
Shift to the left
it decreases oxygen affinity, more 02 release to the tissues
Right shift
Increase oxygen affinity, less 02 release to the tissues
left shift
Hemoglobin in combination with oxygen, it gives pinkness to the skin and mucous membrane and 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 w/ a gestational age of less than three months
Embryonic Hemoglobin
Hemoglobin gower 1
Hemoglobin gower 2
hemoglobin portland
Composed of 2 zeta and 2 epsilon globin chains
Composed of 2 alpha and 2 epsilon
composed of 2 zeta and 2 gamma
the major hemoglobin of the fetus and newborns
Composed 0f 2 alpha and 2 gamma
Produced four months after conception
Fetal Hemoglobin
normal adult hemoglobin
95 to 97 % of hemoglobin in normal adults produced after one year onwards
composed of 2 alpha (141 AA) and 2 beta chains(146 AA)
Hemoglobin A or A1
Constitutes less than 3% of the total hemoglobin
Composed of 2 alpha and 2 delta
Hemoglobin A2
degradation product of HbA2
composed of 2 alpha and 2 delta
Hemoglobin A3
This is the primary hemoglobin in people with sickle cell disease.
Those with Hb S disease have two abnormal beta (βS) chains and two normal alpha (α) chains.
causes the red blood cell to deform and assume a sickle shape when exposed to decreased amounts of oxygen.
Hemoglobin S
is replaced by valine in the 6th position of beta chain
Glutamic Acid
About 2-3% of people of West African descent are heterozygotes for this hemoglobin (have one copy of βC).
This hgb disease (seen in homozygotes
– those with two copies of βC).
instead of glutamic acid , lysine is in B6
It usually causes a minor amount of hemolytic anemia and a mild to moderate enlargement of the spleen.
Hemoglobin C:
Hemoglobin E is one of the most common beta chain hemoglobin variants in the world.
People who are homozygous for Hb E (have two copies of βE) generally have a mild hemolytic anemia, microcytic red blood cells, and a mild enlargement of the spleen.
A single copy of the hemoglobin E gene does not cause symptoms unless it is combined with another mutation, such as the one for beta thalassemia trait.
Hemoglobin E:
an abnormal hemoglobin that occurs in some cases of alpha thalassemia .
It is composed of four beta (β) globin chains and is produced in response to a severe shortage of alpha (α) chains.
Hemoglobin H:
Are acquired hemoglobin variants whose structure has been modified by drugs or environmental chemicals.
do not transport oxygen to the tissue well resulting in
cyanosis.
methemoglobin
sulfhemoglobin
Carboxyhemoglobin
Is a form hgb in its ferric state
Has a brownish to bluish color and does not revert to red on exposure to oxygen.
Peak in the range of 620 – 640 nm at pH 7.1 under
spectral absorption test.
Causes :
Presence of oxidants
Genetic deficiency – decrease activity of MethHB
METHEMOGLOBIN ( HI)
Formed by the irreversible oxidation of Hb of certain drugs and chemicals.
examples :
sulfonomides
phenacetin
acetanilide
Formed by the addition of hydrogen sulfide to Hgb has a
greenish pigment.
If it reaches the critical level in the blood it imparts MAUVE LAVENDER
SULFHEMOGLOBIN
In condition known as enterogenous cyanosis
Sulfhemoglobin
Results from the binding of carbon monoxide to heme iron.
Hb can combine with carbon monoxide with affinity
200 times greater than that of Oxygen.
Carbon monoxide is termed as 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 the hemoglobin it contains.
- Copper Sulfate Specific Gravity -
principle of the copper sulfate sg test
when the drop of donor`s blood dropped into copper sulfate solution comes incased in a sac of copper proteinate, which prevents any change in the sg for abt. 15 sec
