Anatomy The first step in alcohol metabolism by the liver is the forma on of acetaldehyde from alcohol, a chemical reaction catalyzed by A Cytochrome P450 B NADPH-cytochrome reductase P450 C Alcohol oxygenase D Alcohol dehydrogenase 💡 Explanation The first step in alcohol metabolism by the liver is the forma on of acetaldehyde from alcohol, a chemical reaction catalyzed by ✓ Correct Answer: D. Alcohol dehydrogenase