What gives onions their distinctive smell? Correct
The correct answer is sulfur. Onions get their distinctive smell from sulfur compounds present in their cells. When onions are cut or chopped, enzymes are released which break down sulfur-containing amino acids, leading to the formation of various sulfur compounds. These volatile sulfur compounds are responsible for the strong odor associated with onions. While ammonia, sodium, and potassium are important substances, they do not contribute to the characteristic smell of onions. Sulfur compounds are also responsible for the tears that people often shed when cutting onions, as these compounds can react with the moisture in the eyes to form a mild sulfuric acid.