Which reaction is an example of the glycine conjugation pathway?

• A. Phenol to phenolsulfate
• B. Benzoic acid to hippuric acid
• C. Noradrenaline to epinephrine
• D. Antabuse to dithiocarbamic acid

Answer: (B)

Glycine conjugation is a detoxification step where a carboxylic acid is linked to the amino acid glycine to form a more water-soluble compound that can be excreted in urine. The classic example is benzoic acid being conjugated with glycine to make hippuric acid, a process commonly used to remove benzoate from the body after ingestion or drug metabolism. This pathway specifically targets aromatic carboxylic acids for clearance by attaching glycine.

The other options involve different metabolic routes: changing a phenol to a phenol sulfate is sulfation, a separate conjugation pathway; converting noradrenaline to epinephrine is a methylation step in catecholamine biosynthesis, not a glycine conjugation; and transforming Antabuse into dithiocarbamic acid relates to disulfiram metabolism, not the glycine conjugation process.