Answer: Onions produce the chemical irritant known as syn-Propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. ... The synthase enzyme converts the amino acids sulfoxides of the onion into sulfenic acid. The unstable sulfenic acid rearranges itself into syn-Propanethial-S-oxide.
Answers & Comments
Answer: Onions produce the chemical irritant known as syn-Propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. ... The synthase enzyme converts the amino acids sulfoxides of the onion into sulfenic acid. The unstable sulfenic acid rearranges itself into syn-Propanethial-S-oxide.
Explanation:
onion release cells into the air, this cause irriatation.
when this occurs " enzyme " work to alter the amino acid into lachrymator compounds. this irriate our eyes and make tears