Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Biochem Exam 6
Metabolism of Ethanol
| Question | Answer |
|---|---|
| Metabolism of alcohol inthe liver produces | Acetate |
| Ethanol + NAD --> Acetaldehyde + NADH | Alcohol dehydrogenase (ADH) |
| Acetaldehyde + NAD --> Acetate + NADH | Acetaldehyde dehydrogenase (ALDH) |
| Ethanol metabolism occurs mainly in the | Liver |
| Ethanol metabolism oxidizes ethanol to | Acetate |
| Ethanol metabolism reduces NAD+ to | NADH |
| What is the intermediate occuring in ethanol metabolism | Acetaldehyde |
| Two process for convertin gethanol to acetaldehyde exist | Alcohol dehydrogenase (ADH) or the MEOS system |
| With the MEOS system what is not produced | NADH |
| In the case of moderate ethanol consumption, what catalyzes the conversion of ethanol --> acetaldehyde | Alcohol dehydrogenase (ADH) |
| With higher/chronic levels of ethanol consumption, what catabolizes an increasing percentage of the ethanol --> acetaldehyde | Microsomal Ethanol Oxidizing System (MEOS) |
| Where does teh MEOS system occur | On the endoplasmic reticulum |
| What enyzmes is used in the MEOS system | Cytochrom P450 enzyme CYP2E1 |
| What is the cytochrome P450 enzyme which oxidizes ethanol to acetaldehyed in the MEOS process | CYP2E1 |
| What besides ethonal is oxidized in the MEOS system | NADPH |
| What is used as the ultimate oxidzing agent by cytochrome P450 enzymes | Molecular O2 |
| Does CYP2E1 have a higher or lower Km for ethanol than does hepatic ADH | Higher |
| What does ethanol do to other P450 systems | Inibits them |
| The acetate produced from ethanol is activated to | Acetyl CoA |
| Acetyl CoA from Acetate from Ethanol can be used for | TCA cycle, Fatty acid synthesis, Cholesterol biosynthesis, Ketone body synthesis |
| The NADH from ethanol metabolism may be reoxidized via hepatic | Oxidative Phosphorylation or Dehydrogenase Reactions |
| Acetate from ethanol metabolism can be exported from teh liver to extrahepatic cells where it is | Activated to acetyl CoA and catabolized via the TCA cycle in these cells |
| What are three big users of acetate | Skeletal muscle, Heart, and Kidney |
| The ability to metabolize ethanol varies widely from person to person due to the occurrence of | Polymorphism inthe enzymes of ethanol metabolism |
| How many isoenzymes of alcohol dehydrogenase are specific for ethanol | Three of five |
| What isoenzymes of ADH are most specific for ethanol and occur in the liver | ADH 1 and ADH 2 |
| Which as the higher Km ADH 1 or ADH 2 | ADH 2 |
| Which ADH isoenzyme occurs in the upper GI tract | ADH 4 |
| How many isoenzymes of acetaldehyde dehydtrogenas are there | Two, ALDH 1 and ALDH 22 |
| Where do the isoenzymes of ALDH occur | Liver |
| Which ALDH isoenzyme is mitochondrial | ALDH 2 |
| Which ALDH isoenyzme is cystosolic | ALDH 1 |
| What is the major ALDH isoenzyme | ALDH 2 |
| Which ALDH isoenzymes has the higher Km | ALDH 1 |
| The commone genetic variant of this ALDH isoenzyme has relatively low activity that causes toxic levels of acetaldehyde to accumulate leading to nausea, vomiting, and avoidance of ethanol (homozygotes) | ALDH 2 |
| Increased ethanol ingestin results in the induction of the genes for | ADH and ALDH |
| The genes for CYP2E1 are induced in response to | Increased ethanol levels |
| Degradation of CYP2E1 is inhibited by | High ethanol levels |
| NADH levels from high/chronic ethanol ingesting and catabolism may exceed the liver's ability to reoxidize NADH via | Oxidative phosphorylation |
| ADH and ALDH are not regulated b y | NADH/NAD or ATP/ADP-AMP levels |
| The amount of ethanol catabolizm occuring depends on the amount of | Ethanol present |
| Excessive high hepatic NADH levels... TCA Cycle activity | Decreases |
| Isocitrate dehydrogenase is ... by NADH | Allosterically inhibited |
| Excessive high hepatic NADH levels... Beta oxidation | Decreases |
| Excessive high hepatic NADH levels... Glycolysis | Decreases |
| Excessive high hepatic NADH levels... Glycerol-3-phosphate production | Increases |
| Excessive high hepatic NADH levels...Lactate production from pyruvate | Increses |
| Excessive high hepatic NADH levels...Malate prduction from oxaloacetate | Increases |
| A fatty liver may develop because of increased triglyceride synthesis due to | Increased glycerol-3-phosphate syntehsis and decreased beta oxidation |
| Liver damage due to excess acetaldehyde leades to decreased | Protein synthesis, Lipoprotein synthesis, Liporotein export |
| Ketoacidosis may occur with highchronic ethanol ingesting because of | Decreased TCA cycle, Excess Acetyl CoA, Increased ketone body production, Decrease ketone body utilization |
| There is decreased ketone body utilization in high/chronic ethanol ingesting because | The heart and kidney prefer to catabolize acetate over ketone bodies |
| Lactic acidosis may occur with high/chronic ethanol ingestion because | High NADH levels increase lactate prduction from pyruvate |
| At high levels of lactate the liver imports and uses ... amounts of lactate | Decreased |
| Lactate competes with uric acid for excretion by the kidney resulting in | Gout |
| Hypoglycemia in a fast may occur with high/chronic ethanol ingestion because ... hepatic lactate uptake occurs | Decreased |
| A decrease in lactate uptake by the liver cause pyruvate from transamination of alanine to be converted to ... instead of ... | Lactate, Glucose |
| Dihydroxyacetone phosphate is converted to | Glycerol=3-phosphate |
| Hyperglycemia may occur with hihg-chonric ethanol ingetion in a | Fed state |
| Acetaldehyde binds to | Amino acids |
| Acetaldehyde causes ... protein syntehsis | Decreased |
| Lipoprotien syntehsis is decreased due to lack of necessary | Apoproteins |
| Acetaldehyde binds to glutathione decreasing its | Antioxidant activity |
| Increased CYP2E1 activity in the MEOS system ... free radical formation | Increases |
| To correct for hepatic damage the liver attempts wound healing and connetive tissue syntehsis is | Increased |
| What connective tissue is especially used in hepatic repair | Collagen |
Created by:
mhaynes
Popular Medical sets