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Biochem-ETOH Metab
Biochem-Alcohol Metabolism-WVSOM Class of 2012
Question | Answer |
---|---|
in the MEOS system, what enzyme is used? | cytochrome p450 enzyme cyp2e1 |
what is the cofactor in the meos system? is this molecule oxidized or reduced? | nadph; oxidized |
what can the liver make out of acetyl coa? | go into tca, fa synthesis, cholesterol synthesis, ketone synthesis |
how can nadh make energy? | ox phos, various dehydrogenases |
what tissues aside from liver can use acetate? | kidney, heart, skeletal muscle |
which adh isoenzyme has highest km in liver | adh2 |
excessive nadh increases what reactions? | g-3-p production, lactate production, and malate production |
excessive nadh decreases what reactions? | tca activity, b-oxidation, and glycolysis |
what is effect of excess acetaldehyde on protein? | decrease synthesis, decrease lipoprotein synthesis, decrease lipoprotein export |
why does ketoacidosis occur in high etoh intake? | decrease tca cycle activity, decreased acetyl coa going into the tca cycle, increased use of acetate instead of ketones |
why does gout occur in increased etoh levels? | uric acid competes with lactate for excretion |
why do carbon sources decrease for gluconeogenesis inhigh etoh levels? | decreased alanine available, g-3-p not converted to dihydroxyacetone phosphate |
glutathione aside, how else do reactive oxygen species occur in increased etoh? | increased cyp2e1 and increased p450 enzymes |
where does the meos system occur? | on the ER |
which aldh is mitochondrial? which is major oxidizer of aldh? | aldh2; aldh2 |
decreased acetaldehyde clearance more commono in heterozygotes or homozygotes? | homozygotes |
high nadh levels may exceed liver's ability to oxidize via what pathway? | oxidative phos |
why does tca cycle activity decrease in high nadh? | allosteric inhibition of isocitrate dehydrogenase |
why does b-oxidation decrease in high nadh? | not enough nad substrate |
why does glycolysis activity decrease in high nadh? | decreased g3pd activity due to lack of substrate |
why does g3p activity increase in high nadh? | can't go forward from dihydroxyacetone through glycolysis due to decreased g3pd activity |
why does lactate production increase in high nadh? | reaction uses increased nadh to move reaction from pyruvate to lactate |
why does malate production increase in high nadh? | malate comes from oxaloacetate due to nadh favoring that direction of the reaction |
what things contribute to fatty liver? | increased g3p activity and decreased b-oxidation result in increased trigylceride synthesis |
in a pathological situation, what does acetaldehyde bind to? | amino acids |
what lipoprotein contributes to fatty liver? | vldl |
why does gluconeogenesis decrease in high nadh? | decreased dihydroxyacetone, pyruvate, and alanine substrates |