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10 Cards in this Set
- Front
- Back
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Set 03 Q: This type of enzyme inhibitor binds irreversibly to the active site of the enzyme; therefore the inhibition increases with the length of exposure to the substance.
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Irreversible inhibitors (suicide inhibitor) - the nerve gases tabun and sarin are irreversible inhibitors of acetylcholinesterase. They cause symptoms due to increased acetylcholine: blurred vision, sweating, diarrhea, chest tightness, rapid breathing, mental status changes
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Set 03 Q: Defects in this enzyme of the hexose monophosphate shunt result in hemolytic anemia on exposure to oxidative agents
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Glucose-6-phosphate dehydrogenase (G6PDH) - the hexose monophosphate shunt pathway generates NADPH-reducing equivalents, necessary to regenerate glutathione, which protects against oxidative damage to hemoglobin -X-linked recessive disorder - low NADPH leads to hemolytic anemia due to poor RBC defense against oxidizing agents (fava beans, sulfa durgs, primaquine, and anti-TB drugs)
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Set 03 Q: A condition due to deficiency of alpha-L-iduronidase, a lysosomal enzyme, with the accumulation of the mucopolysacchardies heparin sulfate and dermatan sulfate
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Hurler Syndrome - accumulation of mucopolysaccharides in heart, brain, liver, and other organs results in hepatomegaly, dwarfism, gargoyle-like facies, corneal clouding (cataracts), mental retardation, and death by age 10. - get airway obstruction
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Set 03 Q: A condition due to x-linked deficiency of the lysosomal enzyme L-iduronosulfate sulfatase, with accumulation of heparin sulfate and dermatan sulfate
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Hunter Syndrome -results in hepatomegaly, mild mental retardation, NO cataracts, aggressive behavior - less severe smptomatology than Hurler syndrome
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Set 03 Q: A benign condition due to a genetic deficiency of fructokinase, which may be found incidentaly due to an elevated "glucose" concentration in the urine on dipstick testing
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Essential Fructosuria - results in accumulation of fructose in blood and urine, which, like glucose is a reducing sugar that will give a falsely elevated "glucose" concentration on dipstick screening
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Set 03 Q: Deficiency of this glycolytic enzyme leads to the second most common enzyme deficiency hemolytic anemia
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Pyruvate Kinase - deficiency results in inadequate production of ATP, which is needed by Na channels to maintain osmotic equilibrium, the result is membrane lysis - Pyruvate kinase take pyruvate->lactate (NADH->NAD+) to regenerate NAD+ for glycolysis. Essential in RBCs because they cannot run the TCA cycle, they only do glycolysis.
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Set 03 Q: Rarely congenital, this acquired disaccharidase deficiency results in gas, bloating, and watery diarrhea upon consumption of dairy products
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Lactase Deficiency - inability to break down lactose to glucose and galactose leads to osmotic diarrhea as well as increased fermentation by intestinal flora - see low stool pH, high breath H+
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Set 03 Q: This disorder results from a genetic deficiency of galatose-1-phophstate uridyltransferase, with accumulation of galactose-1-phosphate in tissues
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Classic galactosemia -results in failure to thrive shortly after feeding is begun, infantile cataracts, mental retardation, and cirrhosis, with liver failure and death - can be prevented by excluding galactose from the diet early in life - cataracts due to aldose reductase converting galactose to galactitol
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Set 03 Q: This disorder represents the less severe albeit less common form of galactosemia
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Galactokinase-deficient galactosemia - a defect in the first enzyme in the catabolism of galactose results in infantile cataracts WITHOUT hepatocellular complications (liver failure, cirrhosis) -cataracts due to aldose reductase converting galactose to galactitol
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Set 03 Q: This lysosomal storage disease results from a deficiency in the enzyme that adds a mannose-6-phosphate moiety, which is required to target proteins to the lysosome. ex: young child with coarse facies, clouded corneas and restricted movements with an older sibling that died at a young age
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I Cell disease - proteins destined to be targeted through the ER require the presence of a mannose-6-phosphate tag. Without one from the golgi they are released via the default secretory pathway to the OUTSIDE of the cell. Release of such hydrolytic enzymes results in the buildup of partially degraded materials in intracellular inclusions
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