RBC Metabolism Flashcards
Identify the three areas of cel metabolism that are crucial for normal erythrocyte survival and function.
1) RBC membrane
2) Hemoglobin structure and funciona
3) RBC metabolic pathways
Is Glycophorin integral or peripheral? What is its function?
Integral, negative charge and location of antigens
Is Spectrin integral or peripheral? What is its function?
Peripheral, strengthen and perserve deformability
State the structural defects to produce Acanthocytes.
Increase in surface areas = Decrease in intracellular HGB
State the structural defects to produce Bite Cells
Decrease in Spectrin
State the structural defects to produce Sphereocytes
Decrease in Spectrin
State the structural defects to produce Target Cells
Increase in surface area = Decrease in intracellular HGB
What is the protein that delivers iron?
Transferrin
What are the two major tissues where heme synthesis occurs?
BM and liver
Draw Diagram of Heme synthesis! Begin with Succinyl Coenzyme A and glycine and end with heme
Back of PP
Describe the chemical structure of heme
2 Alpha Chains and 2 non alpha chains
What is the reason for “ringed sideroblasts?”
Mitochondrial Buildup of Iron
What is the reason for freshly voided urine from a patient with porphyria to not be red?
Has not oxidized yet
What are the three hemoglobins found in the embryo?
Grower 1, grower 2 and Portland
What is the composition and names of the 3 global chains and what are the percentages of each?
A = 2 alpha and 2 Beta, >95% A2 = 2 Alpha and 2 Delta, 1.5-3% F = 2 Alpha and 2 Gamma,
Characterize the oxygen affinity of R (relaxed) and T (tense) hemoglobin.
R is affinity for O2
T has a lower affinity for O2
What happens in a left shift and where does it occur?
Uptake of O2 , lung
What happens in a right shift and where does it occur?
Release of O2, Tissue
What happens to PH, 2-3 DPG levels, and Temperature in a shift to the left?
PH increases
2,3 DPG levels decreases
Temperature decreases
What happens to PH, 2-3 DPG levels, and Temperature in a shift to the right?
PH decreases
2,3 DPG levels increases
Temperature increases
List the three abnormal hemoglobins that are unable to transport or deliver oxygen.
Carboxyhemoglobin
Methemoglobin
Sulfahemoglobin
State the main source of ATP production in mature RBCs
Mitochondria
Name that metabolic pathway that generates most of the RBC ATP.
Emden meyerhof Pathway
State the major function of Eden Meyerhof pathway.
Anaerobic glycolysis = energy
State the major function of Hexose monophosphate shunt.
Protects RBCs from environmental oxidants
State the major function of Methemoglobin Reductase Pathway.
Maintains iron in the ferrous (2+) state
State the major function of Leubering-Rapport Shunt.
Synthesis of 3,3 DPG
State that changes in RCS leading to demise in 120 days
As enzymes break down, lose of energy production and deformability and can’t not get through he cords of the spleen = phagocytize by RES cells.
Compare and contrast steps in extravascular Versus Intravascular breakdown of RBCs
(on back of objectives)
Extravascular = 90%, within RES cells, RES phagocytize, Iron is couples to transferrin, Bilirubin to Urobilinogen and excreted
Intravascular= 10%, within blood vessels, Haptoglobin pricks up free HGB, go to liver where Bilirubin to Urobilinogen and excreted
What is the level of Haptoglobin in the presence of intravascular hemolysis?
Decreased
State the main protein carrier for Bilirubin
Albumin
State the main protein carrier for Hemoglobin
Haptoglobin
State the main protein carrier for Iron
transferrin
Define Porphyria
Disorder of heme synthesis
Define Porphyrin
Oxidized porphyrinogen, stable, florescent pinkish-red “port wine”
Define Porphyrinogen
Precursor to Porphyrin, colorless, non fluorescent, highly unstable. Quickly oxidizes to porphyrin
