Explain how alcohol is detoxified by the liver.  

Alcohol is detoxified in the liver by enzymes like alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) which metabolize it.

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To explain how alcohol is detoxified in the liver, look into the roles of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).

Alcohol dehydrogenases (ADHs) are a class of dehydrogenase enzymes, meaning that they catalyze reactions involving alcohols. Alcohol can be quite dangerous for the body since it can have a...

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To explain how alcohol is detoxified in the liver, look into the roles of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).

Alcohol dehydrogenases (ADHs) are a class of dehydrogenase enzymes, meaning that they catalyze reactions involving alcohols. Alcohol can be quite dangerous for the body since it can have a negative impact on the human nervous system. ADH serves to defend the human body against the alcohol molecule by metabolizing it.

ADH, which can be found in the liver, metabolizes ethanol—a 2-carbon alcohol. ADH breaks ethanol down to ethanal (i.e. acetaldehyde). Ethanal, which is highly reactive and toxic enough to damage mitochondria, is metabolized by an enzyme called aldehyde dehydrogenase (ALDH). ALDH breaks ethanal down to acetate. Acetate, in the form of acetyl-CoA, is processed via the citric acid cycle, yielding water and carbon dioxide.

Here is a basic chemical overview of what occurs:

ADH Oxidation:

Ethanol + NAD+ --> Ethanal + NADH

ALDH Oxidation:

Ethanal + H20 + NAD+ --> Acetate + NADH

Acetyl-CoA Synthetase:

Acetate + CoA + ATP <=> Acetyl-CoA + Pyrophosphate + AMP

Citric Acid Cycle:

Acetyl-CoA --> CO2 + H2O

It is worth mentioning that, in the liver, there exists an alternative pathway for the breakdown of ethanol. This pathway is called the microsomal ethanol oxidizing system (MEOS). It is not used very much in those who consume alcohol once in a while; its use is more apparent in individuals who consume alcohol on a regular basis.

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