Which statement correctly describes how alcohol is eliminated from the body?

Which statement correctly describes how alcohol is eliminated from the body?

• A. Oxidation in the liver, converting alcohol to acetic acid, then to carbon dioxide and water.
• B. Excretion via lungs.
• C. Direct excretion in urine without metabolism.
• D. Absorption into adipose tissue.

Answer: (A)

The main idea is that alcohol is eliminated from the body primarily through liver metabolism. In the liver, ethanol is oxidized to acetaldehyde, then acetaldehyde is oxidized to acetate (acetic acid). This acetate is further processed to acetyl-CoA and enters energy pathways, eventually yielding carbon dioxide and water. That metabolic route explains why most alcohol is cleared from the body, rather than being excreted as alcohol itself. A small portion is exhaled through the lungs, but this is only a minor route compared with metabolism. Direct excretion in urine without metabolism happens only to a small extent, not the main pathway. Alcohol is not stored in adipose tissue as the primary elimination mechanism.

The main idea is that alcohol is eliminated from the body primarily through liver metabolism. In the liver, ethanol is oxidized to acetaldehyde, then acetaldehyde is oxidized to acetate (acetic acid). This acetate is further processed to acetyl-CoA and enters energy pathways, eventually yielding carbon dioxide and water. That metabolic route explains why most alcohol is cleared from the body, rather than being excreted as alcohol itself.

A small portion is exhaled through the lungs, but this is only a minor route compared with metabolism. Direct excretion in urine without metabolism happens only to a small extent, not the main pathway. Alcohol is not stored in adipose tissue as the primary elimination mechanism.