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16 Cards in this Set
- Front
- Back
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Another Name for the Pentose Phosphate Pathway |
Hexose Monophosphate shunt 6- phosphogluconate pathway |
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What is produced by the pentose phosphate pathway |
NADPH and H+ Pentose sugar |
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Where does the Pentose Phosphate Pathway occur |
1. Liver, lactating mammary gland, adipose tissue 2. Adrenal Cortex, Testes, Ovaries 3. Erythrocytes (Provides NADPH for reduction of Glutathione) 4. White Blood cells and Macrophages (Provides NADPH for Phagocytosis |
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What is the Oxidative Phase of the Pentose phosphate pathway |
1. Glucose 6-Phosphate (G6P) converted to 6-phosphogluconolactone by G6PD releasing 1 NADPH 2. 6-phosphogluconolactone spontaneously converts to 6-phosphogluconate 3. 6-Phosphogluconate converts to Ribulose 5 - Phosphate via 6-phosphogluconate dehydrogenase releasing 1 NADPH and 1 CO2 |
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What is the regulated Enzyme in the Oxidative phase of the Pentose phosphate pathway |
G6PD |
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What happens to excess ribulose 5-phosphate |
They are converted to glycolytic intermediates 2 molecules fructose 6-P 1 Molecule Glyceraldehyde 3-P |
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Enzymes of the Non-oxidative phase of the pentose phosphate pathway |
1. Transketolase (TPP cofactor [Thiamine pyrophosphate] ) 2. Transaldolase 3. Epimerase 4. Isomerase |
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Uses of NADPH |
1. Reduction and Detoxification of Hydrogen Peroxide 2. For Phagocytosis in WBC's 3. Synthesis of Nitric Oxide (NO) 4. Cytochrome P450 system 5. Reductive biosynthetic reactions in fatty acid synthesis and synthesis of steroid hormones. |
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How does NADPH aid in reduction of Hydrogen Peroxide in RBC's |
Reduces oxidized glutathione to two reduced glutathiones so that glutathione peroxidase can oxidize the glutathione reducing H2O2 to H2O+O2 |
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What is G6PD deficiency |
X-linked recessive disorder High Prevalence in Middle Ease, Africa, Asia, and Mediterranean. Reduced G6PD results in impaired formation of NADPH = less 2GSH causing Hemolysis |
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What are stressors of Hemolysis |
1. Infections 2. Fava Beans 3. Antimalarials 4. Sulfa Drugs |
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What are the signs of Hemolysis |
1. Jaundiced (increased serum bilirubin) 2. Fallen Hemoglobin 3. Red/brown urine positive for hemoglobin |
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What are Heinz Bodies |
Caused by G6PD deficiency, resulting in formation of denatured proteins as insoluble masses (Heinz Bodies). The denaturing is via formation of unwanted disulfide bonds. |
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Mechanism of Hemolysis in G6PD deficiency |
1. Oxidative Stress 2. GSH converted to GS-SG for detoxification of oxidants 3. Increased requirement for NADPH 4. Oxidants accumulate 5. Fatty acids damaged weakening membrane 6. RBC lysis |
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Less Severe form of G6PD deficiency |
G6PD A- : Only shows symptoms when exposed to stressor |
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Most severe form of G6PD deficiency |
G6PD Mediterranean : Constant Hemolysis
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