Decarboxylation of lysine, ornithine, and arginine leads to the formation of:

• A. Amines
• B. Urea
• C. CO2
• D. Ammonia

Answer: (D)

The decarboxylation of amino acids such as lysine, ornithine, and arginine specifically results in the production of ammonia. This process involves the removal of a carboxyl group (-COOH) from the amino acid, which results in the release of carbon dioxide (CO2) as a product. However, the key metabolic outcome is the transformation of the amino acids into biogenic amines, with the significant production of ammonia during this reaction.

When the amino acids lose their carboxyl groups, the remaining structure can lead to the formation of ammonium ions (NH4+) or ammonia (NH3) in solution, depending on the pH of the environment. The generation of ammonia can contribute to the alkaline environment of certain bacterial cultures, which can be an important factor in identifying specific microorganisms based on their metabolic activities.

The other options do not apply in this context since the direct output of decarboxylation is not primarily about forming urea or simply CO2 alone; while amines are formed, the focus here is on the ammonia produced as a resulting compound, which is produced in significant quantities during this process.