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18 Cards in this Set
- Front
- Back
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What is C2H5OH
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ethanol molecule
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Alcohol found in alcoholic beverages is formed how?
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In yeast cells by fermentation.
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How is fermentation carried out?
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It is a long series of enzymatic oxidation-reduction reactions carried out without O2 participation, and it provides energy for the cell.
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The final biochemical conversions that produce alcohol are pyruvate-----acetylaldehyde-----ethanol. TRUE/FALSE
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TRUE.
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What enzyme is required for the conversion of pyruvate to acetylaldehyde?
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pyruvate decarboxylase. This enzyme is present in yeast, but is lacking in human cells. In yeast cells, ethanol is the final metabolite and is excreted from the cell.
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Industrial fermentation is carried out by the addition of what?
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yeast to a mixture of sugar containing substrates and water.
The end result of the fermentation process is the conversion of simple sugar into alcohol and CO2. |
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In the above example, does the conc. of alcohol have a maximum yield?
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Yes.It will not exceed 15% because yeast ceases to metabolize under higher concentrations of alcohol.
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Is table wine the result of natural fermentation?
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Yes. It stops when the alcohol conc. reaches 12 to 14%.
Brewing, fermentation is halted when alcohol conc reaches 4-6%. Liquors usually contain 40-43% of pure alcohol. |
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Does alcohol have a dose dependent biphasic effect on the CNS?
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Yes. The first phase is given by energizing or stimulating effects, the 2nd phase is a sedative or pharmacological effect.
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Is alcohol always considered foriegn to the body?
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No. It has been established that blood plasma of abstaining individuals has app. 0.039 mg of alcohol per dl of blood. This is considered endogenous, generated inside the body.
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How does endogenous alcohol come to be?
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It is the result of microbial fermentation of ingested sugars in the gut, absorbed by the mucus membrane and entering the blood stream. This level is considered insignificant.
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Many studies confirm that ethanol is an intracellular metabolitr. TRUE/FALSE
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TRUE.
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Where is alcohol dehydrogenase found?
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It is found in liver cells. It is an enzyme that plays a key role in the reversible reaction of alcohol conversion into acetylaldehyde.
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It is also less known that alcohol dehydrogenase is present in the cells of all tissues, including neurons in the brain. TRUE/FALSE
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TRUE.
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Many authorities believe that a natural function of AD(alcohol dehydrogenase) is the oxidation of alcohol entering the body from alcoholic beverages. TRUE/FALSE
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TRUE.
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In human cells, how can ethanol be produced?
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In mitochondria from acetyl CoA by its conversion into acetate, which in return is reduced by aldehyde dehydrogenase to acetylaldehyde. Acetylaldehyde is further reduced by alcohol dehydrogenase to ethanol.
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Does the cell produce the ethanol for a reason?
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Biochemical reactions that produce ethanol participate in the energetic metabolism of the cell, shuttling energy between mitochondria and cytoplasm and then removing energy releasing substrates from mitochondria and the cell as a whole.
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The need for energy transfer between mitochondria and cytoplasm is due to what?
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Some differences in energetic processes in these parts of the cell.
In the cytoplasm energy is primarily generated by glycolysis, an anerobic split of glucose to pyruvate and lactate. |
