Alcohol Metabolism Flashcards
How much energy per gram does alcohol provide?
7kcal/gram
What are the consequences of alcoholism?
Fatty liver, hepatic disease (cirrhosis), and lactic acidosis
Does alcohol possess any nutrients?
No
Where is ethanol readily absorbed?
Throughout the entire GI tract
Where is ethanol primarily degraded?
In the liver
The liver converts ethanol into what?
Acetaldehyde then to acetate
Both steps of conversion of ethanol to acetaldehyde then to acetate in the liver produce what?
NADH
What can acetate possibly turn into next?
Acetyl CoA
What are the three enzyme systems that break down alcohol?
Alcohol dehydrogenase, MEOS (microsomal ethanol oxidizing system aka Cytochrome P-450 System), and catalase
What is the least active enzyme system for the breakdown of alcohol?
Catalase
What is used in the presence of catalase for alcohol breakdown?
Hydrogen peroxide
What enzyme is responsible for oxidizing ethanol into acetaldehyde?
Alcohol dehydrogenase
What enzyme is responsible for oxidizing acetaldehyde into acetate?
Acetaldehyde dehydrogenase
NADPH is produced in which enzyme systems for alcohol breakdown?
Both alcohol dehydrogenase AND MEOS
What is the location of the alcohol dehydrogenase pathway?
Cytoplasm of liver cells
What is required for alcohol dehydrogenase to work?
NAD
At what point is alcohol dehydrogenase at 1/2 maximum velocity?
At cellular concentration of ethanol
At what point is alcohol dehydrogenase saturated?
At 3-4 times the Km
At what point can alcohol no longer be oxidized by alcohol dehydrogenase?
Concentrations beyond 4 times Km
What is the toxic level of alcohol?
50-100 mg/dL
What is the reason that ethanol is able to enter the cells easily?
High lipid solubility
When alcohol dehydrogenase is saturated, what enzyme system must take over for breakdown of alcohol?
MEOS