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Questions and Answers
Which of the following is NOT a primary area of RBC biology that is crucial for normal erythrocyte survival and function?
Which of the following is NOT a primary area of RBC biology that is crucial for normal erythrocyte survival and function?
- Mitochondrial function (correct)
- Hemoglobin structure and function
- RBC metabolism
- Normal chemical composition and structure of the RBC membrane
Peripheral proteins span from the outer surface of the membrane to the inner surface.
Peripheral proteins span from the outer surface of the membrane to the inner surface.
False (B)
What is the main structural component of the RBC membrane?
What is the main structural component of the RBC membrane?
phospholipid bilayer
Loss of ____ leads to a decrease in the phosphorylation of spectrin and a loss of membrane deformability
Loss of ____ leads to a decrease in the phosphorylation of spectrin and a loss of membrane deformability
Which of the following ions are freely permeable to the RBC membrane?
Which of the following ions are freely permeable to the RBC membrane?
RBC volume and water homeostasis are maintained by controlling the intracellular concentrations of chloride and bicarbonate.
RBC volume and water homeostasis are maintained by controlling the intracellular concentrations of chloride and bicarbonate.
Match the following terms with their descriptions:
Match the following terms with their descriptions:
What happens to the intracellular concentration of sodium and calcium when ATP is depleted during storage?
What happens to the intracellular concentration of sodium and calcium when ATP is depleted during storage?
What percentage of ATP needed by red blood cells is generated by glycolysis?
What percentage of ATP needed by red blood cells is generated by glycolysis?
Red blood cells use oxidative metabolism to produce ATP.
Red blood cells use oxidative metabolism to produce ATP.
What is the main reason red blood cells rely on anaerobic metabolism?
What is the main reason red blood cells rely on anaerobic metabolism?
The Luebering-Rapoport shunt permits the accumulation of ________ in red blood cells.
The Luebering-Rapoport shunt permits the accumulation of ________ in red blood cells.
Match the following pathways with their primary function in red blood cells:
Match the following pathways with their primary function in red blood cells:
Which of the following best describes the effect of increased 2,3-DPG levels on the hemoglobin-oxygen dissociation curve?
Which of the following best describes the effect of increased 2,3-DPG levels on the hemoglobin-oxygen dissociation curve?
The tense form (T form) of hemoglobin has a higher affinity for oxygen than the relaxed form (R form).
The tense form (T form) of hemoglobin has a higher affinity for oxygen than the relaxed form (R form).
What is the primary role of hemoglobin?
What is the primary role of hemoglobin?
Match the form of hemoglobin with its oxygen affinity:
Match the form of hemoglobin with its oxygen affinity:
How can transfusion of stored blood cause a shift to the left of the hemoglobin-oxygen dissociation curve?
How can transfusion of stored blood cause a shift to the left of the hemoglobin-oxygen dissociation curve?
RBCs should be stored in the liquid state at a temperature range of ____.
RBCs should be stored in the liquid state at a temperature range of ____.
2,3-DPG can re-form in stored RBCs after in vivo circulation.
2,3-DPG can re-form in stored RBCs after in vivo circulation.
The rate of restoration of 2,3-DPG is NOT influenced by which of the following?
The rate of restoration of 2,3-DPG is NOT influenced by which of the following?
CPDA-1 can only be stored for up to 21 days.
CPDA-1 can only be stored for up to 21 days.
Match the following anticoagulant preservative solutions with their functions:
Match the following anticoagulant preservative solutions with their functions:
Top three benefits of RBC additive solutions:
- extends shelf-life of RBCs to __ days by adding nutrients
- allows for the harvesting of more _______ from the unit
- produces a packed RBC of _____ that is easier to infuse
Top three benefits of RBC additive solutions:
- extends shelf-life of RBCs to __ days by adding nutrients
- allows for the harvesting of more _______ from the unit
- produces a packed RBC of _____ that is easier to infuse
what are the four additive solutions licensed in the United States.
what are the four additive solutions licensed in the United States.
Match the RBC additive solutions with their common ingredients:
Match the RBC additive solutions with their common ingredients:
Autologous transfusion allows individuals to donate blood for their own use to meet their needs for blood transfusion.
Autologous transfusion allows individuals to donate blood for their own use to meet their needs for blood transfusion.
Rejuvenation of RBCs is the process by which ATP and 2,3-DPG levels are restored or enhanced by _______.
Rejuvenation of RBCs is the process by which ATP and 2,3-DPG levels are restored or enhanced by _______.
FDA-approved rejuvenation solution contains which of the following
FDA-approved rejuvenation solution contains which of the following
rejuvenated RBCs may be prepared up to five days after expiration when stored in CPD, CPDA-1 and AS-1 storage solutions
rejuvenated RBCs may be prepared up to five days after expiration when stored in CPD, CPDA-1 and AS-1 storage solutions
why do rejuvenated RBCs need to be washed before infusion?
why do rejuvenated RBCs need to be washed before infusion?
RBC rejuvenation is time-consuming and expensive. Why would this process be used?
RBC rejuvenation is time-consuming and expensive. Why would this process be used?
rejuvenated RBCs must be transfused within ____ after washing, otherwise it must be frozen for long-term storage.
rejuvenated RBCs must be transfused within ____ after washing, otherwise it must be frozen for long-term storage.
Flashcards
RBC membrane
RBC membrane
A semipermeable membrane that encloses the red blood cell, composed of a lipid bilayer and a protein cytoskeleton. It allows for deformability, permeability, and maintains cell volume.
Integral proteins
Integral proteins
Proteins that extend across the entire RBC membrane, from the outer to the inner surface. They play a vital role in its structure and function.
Peripheral proteins
Peripheral proteins
Proteins located only on the inner surface of the RBC membrane. They help maintain the membrane's shape and stability.
RBC deformability
RBC deformability
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RBC permeability
RBC permeability
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Spherocytes
Spherocytes
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Bite cells
Bite cells
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RBC membrane loss
RBC membrane loss
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Glycolysis in RBCs
Glycolysis in RBCs
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Pentose Phosphate Pathway in RBCs
Pentose Phosphate Pathway in RBCs
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Methemoglobin Reductase Pathway
Methemoglobin Reductase Pathway
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Luebering-Rapoport Shunt
Luebering-Rapoport Shunt
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2,3-Diphosphoglycerate (2,3-DPG)
2,3-Diphosphoglycerate (2,3-DPG)
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Hemoglobin-Oxygen Dissociation Curve
Hemoglobin-Oxygen Dissociation Curve
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Right Shift of the Hemoglobin-Oxygen Dissociation Curve
Right Shift of the Hemoglobin-Oxygen Dissociation Curve
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Left Shift of the Hemoglobin-Oxygen Dissociation Curve
Left Shift of the Hemoglobin-Oxygen Dissociation Curve
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Factors Affecting Hemoglobin-Oxygen Affinity
Factors Affecting Hemoglobin-Oxygen Affinity
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Study Notes
Red Blood Cell (RBC) Biology and Preservation
- RBCs have a crucial lifespan of 120 days, dependent on three key biological areas:
- Normal membrane composition and structure
- Hemoglobin structure and function
- RBC metabolism
- Defects in these areas shorten lifespan. RBC metabolic pathways are primarily anaerobic to avoid consuming the oxygen they carry.
RBC Membrane
- Composed of a semipermeable lipid bilayer with a protein cytoskeleton:
- Phospholipids form a bilayer, proteins traverse it.
- Integral proteins: Span the membrane.
- Peripheral proteins: Located on the inner side of the membrane.
- Asymmetrical organization: External layer (glycolipids, choline phospholipids); Internal layer (amino phospholipids).
- Chemical composition: 52% proteins, 40% lipids, 8% carbohydrates.
Deformability
- RBCs must stay flexible to survive.
- Loss of ATP decreases spectrin phosphorylation, thus reducing deformability.
- Increased calcium deposition stiffens the membrane.
- Loss of membrane leads to abnormal shapes, like spherocytes (reduced surface area) and bite cells (membrane missing).
Permeability
- Membrane controls RBC volume and prevents hemolysis.
- Freely permeable to water and anions (Cl-, HCO3-).
- Impermeable to most cations (Na+, K+).
- Intracellular Na+/K+ ratios (1:12) and (25:1) are maintained via ATP-driven pumps.
- Calcium (Ca2+) actively pumped out by ATPase pumps.
- Storage depletes ATP; Na+, Ca2+ accumulate; K+, water are lost; and cells become rigid.
RBC Metabolism
- RBCs lack a nucleus and mitochondria, making oxidative metabolism impossible.
- RBC ATP production is primarily anaerobic.
- Metabolic pathways are divided:
- Glycolysis: Generates 90% of RBC ATP.
- Pentose phosphate pathway: Produces 10% of RBC ATP.
- Methemoglobin reductase pathway: Defects impact post-transfusion survival and function.
- Luebering-Rapoport shunt: Allows 2,3-diphosphoglycerate (2,3-DPG) accumulation.
- 2,3-DPG significantly affects hemoglobin's oxygen affinity, impacting RBC function post-transfusion.
Hemoglobin-Oxygen Dissociation Curve
- Hemoglobin's role is gas transport (oxygen to tissues, carbon dioxide excretion).
- 2,3-DPG is a key regulator of hemoglobin's oxygen affinity.
- Deoxyhemoglobin (T form):
- Widened space between beta chains.
- 2,3-DPG binding on a mole-for-mole basis.
- Anionic salt bridges between chains.
- Lower oxygen affinity.
- Oxyhemoglobin (R form):
- Beta chains pulled together.
- 2,3-DPG expelled.
- Higher oxygen affinity.
- Respiratory movement: allosteric changes during oxygen loading/unloading.
- Hemoglobin-oxygen dissociation curve: sigmoid curve, not directly proportional to oxygen partial pressure.
- Oxygen dissociation curve position depends on three ligands: H+ ions, CO2, and organic phosphates (2,3-DPG being most important).
- Shift to the right:
- Caused by hypoxia.
- Increased 2,3-DPG levels alleviate tissue oxygen deficit.
- Decreased hemoglobin oxygen affinity, increases oxygen delivery to tissues.
- Shift to the left:
- Increased hemoglobin-oxygen affinity.
- Decreased oxygen delivery to tissues (only 12% oxygen released to tissues).
- Caused by multiple transfusions of 2,3-DPG-depleted blood.
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