What is the correct sequence of alcohol metabolism in the liver?

• A. Ethanol is converted directly to acetate by liver enzymes.
• B. Ethanol is converted to acetaldehyde, then to acetate.
• C. Acetaldehyde is converted to ethanol and then to acetate.
• D. Acetate is converted to ethanol and then to acetaldehyde.

Answer: (B)

In the liver, ethanol is processed in two oxidation steps, with an important intermediate. First, ethanol is converted to acetaldehyde by the enzyme alcohol dehydrogenase. Then acetaldehyde is rapidly converted to acetate by aldehyde dehydrogenase. This two-step sequence explains why acetaldehyde is described as the intermediate and why acetate is the end product in this pathway.

Directly turning ethanol into acetate would skip the intermediate acetaldehyde, which is not how the body handles alcohol. The idea of acetaldehyde turning back into ethanol doesn’t happen in normal metabolism, and acetate isn’t formed before ethanol in the sequence. So the correct flow is ethanol → acetaldehyde → acetate.