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17 Cards in this Set
- Front
- Back
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Purpose of RBC Metabolism
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Keep a reduced environment and E metabolism
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Ox + Hb--> HbO2--> O2- + MetHb
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O2- Bad bc superoxide anion
MetHb Bad bc does not bind O2 |
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Met Hb (Fe+3) ---> Hb (Fe+2)
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Met Hb reductase
NADH---> NAD+ from glycolysis as GAPDH ---> 1,3 diPglycerate |
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O2- --->O2
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Superoxide dismutase
Produce peroxide bad! |
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2 GSH ---> GSSG
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Glutathione peroxidase
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GSSG--->2GSH
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Glutathione Reductase
NADPH--->NADP+ from PPP from Glc 6PDH & 6-Pgluconate DH |
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Glucose 6-P dehydrogenase deficiency
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Low NADPH, NADH
Glutathione will be oxidized ---> GSSG Peroxide & MetHb accumulates |
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What happens when peroxide accumulates?
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Membrane damage
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What happens when MetHb increases?
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Forms granules called Heinz bodies--->distort RBC shape-->RBC lysis--->Hemolytic anemia
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What other cmpds can change the reduced environment?
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Anti-malarial drugs bc they accept electrons from NADPH/NADH
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Effect of anti-malarial drugs
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accept e from NADPH/NADH ---> cannot maintain reduced environment---> high GSSG, MetHb--->Heinz bodies form--->distort RBC--->lysis
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Pyruvate Kinase deficiency (PK)
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PEP, glycerate 2-P, glycerate 3-P accumulate upstream
Pyruvate, lactate, ATP lower downstream No ATP--->needed for Na/K ATPase--->maintain plasma membrane--->cells lyse |
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Hemoglobinopathies
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Abnormalities in globin polypeptides
1. Change in aa sequence of globin 2. Imbalance of alpha or beta chains of Hb ie: alpha/beta-thalassemia |
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Sickle Cell Anemia
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aa change from glutamic acid (negatively charged) GAG to Valine (neutral) GUG
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When does RBC turn sickle?
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Hydrophobic "patch" in oxy/deoxy HbS matches with complementary "groove"--->ppt-->distort RBC shape-->sickle shape
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When can sickle cell anemia occur?
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Acidosis
Exercise-high H+ and CO2 High Altitude-low pO2 Hypoxia |
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Hemoglobin M
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aa changes from Tyr to Hist
Fe+3 becomes more stable than Fe+2 Fe+3 is MetHb and does not bind O2--> lysis |
