2. Hemoglobin Flashcards
Place where heme is synthesized
Mitochondria
Composition of a normal Hgb
- 4 heme molecules
- 4 globin molecules
RBC stages that produce hemoglobin
- Pronormoblast
- Basophilic normoblast
- Polychromatophilic normoblast
- Orthochromic normoblast
- Reticulocyte
Composition of the globin portion of Hgb
- 2 α chains
- 2 non-α chains
Globin chains controlled by Chromosome 16
α & ζ chains
Globin chains controlled by Chromosome 11
β, γ, δ, and ε chains
Function of Hgb
Transport of gases
The primary Hgb for gas transport in the body
Oxyhemoglobin
Hgb variant that contains Fe3+ instead of Fe2+
Methemoglobin
Heme is composed of
- protoporphyrin IX ring
- Fe2+
Methemoglobin production is controlled by
Methemoglobin reductase pathway
Hgb variant formed as a result of oxidation of Hgb by materials containing sulfur
Sulfhemoglobin
Hgb variant that can lead to cyanosis
Sulfhemoglobin
Hgb variant resulting from heme iron-binding carbon monoxide
Carboxyhemoglobin
Hgb variant that has a high O2 affinity; will not give up O2 to tissues to the tissues easily
Carboxyhemoglobin
Process of energy production utilized by RBCs
Anaerobic glycolysis: Embden-Meyerhof pathway
Functions of the Embden-Meyerhof pathway
- maintain cation gradients
- maintain RBC membrane flexibility
- supply offshoot pathways
3 offshoot pathways of the Embden-Meyerhof pathway
- hexose monophosphate shunt
- methemoglobin reductase pathway
- Rapoport-Luebering pathway
Embden-Meyerhof pathway offshoot; protection of the RBC from oxidant damage by production of reduced glutathione
Hexose monophosphate shunt
Embden-Meyerhof pathway offshoot; maintains iron in the ferrous form
Methemoglobin reductase pathway
Embden-Meyerhof pathway offshoot; regulation of O2 delivery to tissues by the production of 2,3-bisphosphoglycerate (2,3-BPG)
Rapoport-Luebering pathway
Produced in hexose monophosphate shunt for protection of RBCs from oxidant damage
Reduced glutathione
Produced in the Rapoport-Luebering pathway for regulation of O2 delivery
2,3-BPG
Hgbs found during the embryonic stage
Gower 1
Gower 2
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