In fact, it becomes so unstable that in the presence of water, it basically spontaneously breaks. So this ring spontaneously opens up and breaks. And so the oxygen here essentially attacks this carbon, forming this carbon oxygen double bond. And the two HS go onto this nitrogen here. So we formed this glutamate semiaaldehyde. Now, the glutamate semi aldehyde is actually important, as we'll see in just a moment when we'll discuss Arginine, because Arginine also goes through this intermediate glutamate semi aldehyde.