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2014-03-19 06:54:31
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  1. What stages in RBC development is hemoglobin made in what percent?
    • 65% in metarubricyte stage
    • 35% in reticulocyte stage
  2. How many molecules of hgb per RBC? % weight of RBC? % volume of RBC?  What is the charge on RBC surface?
    • 640 million hgb/RBC
    • 95% weight
    • 33% volume
    • Negative charge due to negative charge of hgb
  3. What is the structure of a normal hgb molecule? and what is the % of each?
    • 4 heme + 4 globin chains
    • Protein: 96% (globin chains)
    • Heme: 4% (protoporphyrin ring, iron)
  4. Describe iron delivery to the cell during hemoglobin synthesis in detail
    • Transferrin transports iron (Fe3+) into the cell
    • Most is transferred to the mitochondria and converted to Fe2+
    • Any excess aggregates in the cytoplasm as ferritin
  5. Name the stages of hemoglobin synthesis
    • Iron delivery to the cell
    • Protoporphyrin synthesis
    • Globin synthesis
  6. Describe protoporphyrin synthesis during hemoglobin synthesis in detail
    • Succinyl-CoA and glycine enter the mitochondria
    • ΔALA (delta aminolevulinic acid) creates porphobilinogen, which is then converted into uroporphyrinogen, then coproporphyrinogen, and finally protoporphyrin
    • **ΔALA is the rate limiting step
    • Protoporphyrin is combine with Fe and heme is released from the mitochondria
  7. Which globin chain alleles are on which chromosome?
    • Chromosome 11: ε, Gγ (glycine), Aγ (alanine), δ, β
    • Chromosome 16: ζ, α, α
  8. Describe globin chain production amounts from fetus to adulthood
    • ζ and ε: embryonic; 100% at 0mo very low at 2mo, ends at 4mo
    • γ: fetal; very high at 2 mo, sharply drops 9mo (birth), persists slightly throughout life
    • α: very high at 2 mo and persists throughout life
    • β: adult; slowly raises to 20% through 9mo (birth) then quickly spikes around 3mo after birth and persists throughout life
    • δ: very low development that begins around 8mo and persists (low) throughout life
  9. What are the various types of abnormal hemoglobins w/ combo of globin chains (detailed)
    • H (β4): occurs in alpha thalassemia
    • Bart's (γ4): occurs in alpha thalassemia
  10. What are the various types of normal hemoglobins w/ combo of globin chains (detailed)
    • Embryonic hemoglobin
    • 3 weeks to 3 months in fetus
    • Gowers type 1 (ζ2ε2)
    • Gowers type 2 (α2ε2)
    • Fetal hemoglobin
    • 3 mos in fetus to 9-12mo after birth
    • F (α2Aγ2)
    • F (α2Gγ2)
    • Adult hemoglobin
    • Increases after 12mo to normal levels
    • A (α2β2)
    • A22δ2)
    • A1C2[β-NH-glucose]2)
  11. What is the approximate Hgb composition in a normal adult blood cell?
    • Hgb A: 95-97% (includes less than 5% Hgb A1C)
    • Hgb A2: 2-3%
    • Hgb F: 1-2%
    • *note - Hgb F represents 70-90% of all hgb in RBC at birth
  12. What are the two normal states of hemoglobin and what regulates them?
    • Oxyhemoglobin
    • Deoxyhemoglobin
    • 2,3-diphosophoglycerate (2,3-DPG) regulates O2 affinity
  13. What are the abnormal hemoglobin states of clinical importance with a brief description
    • Carboxyhemoglobin: CO replaces CO2
    • *note - CO binds 200x more firmly than O2
    • Methemoglobin: oxidized hemoglobin
    • (Fe3+ instead of Fe2+)
    • Sulfhemoglobin: sulfur replaces iron