Sorry for my late reply. Because we're living in different time zones, I couldn't read your posting till this afternoon. First of all, I think that hydroquinone and hydrogen peroxide will explode in the presence of (bombardier beetle's) catalase. Of course I do not have any evidence. I wonder if Dr. Shildknecht had done that experiment by himself. (I mean, if he had mixed HQ and H2O2 then add catalase in vitro.) But according to Dr.Schildknecht's paper, explosion occurs in the presence of catalase. The more detailed explanation is on his another paper in an entimology journal, but I'm absolutely no entimologist so I did not read that paper. But if you want, I'll try to read that and post my understanding. In his rather brief review paper, Dr.Schildknecht did not mention the reaction mechanism. But as a chemist, I can suggest a plausible mechanism of my own speculation. (vide infra) I'll post the correct reaction mechanism if I can find his paper on the entimology journal. ---> Catalase contains a heme group. In the course of reaction, the heme group forms oxrene intermediate, which is commonly called compound I, consists of a rather rare Fe(IV) attached to a oxygen atom by covalent double bond. In the normal circumstance this oxrene intermediate oxidezes H2O2 molecule to form water and oxygen gas. But maybe in the presence of HQ it oxidizes HQ instead, to make quinone with a lot of heat. Again, it's my speculation based on my chemical and enzymological knowledge. What seems to be certain, at this point, is that there is no such things like "inhibitor", or at least Dr.Schildknecht did not mention about that. If you have any more questions, I'll be glad to try to answer them. It's kind of challenging to me, and I'm enjoying it very much. Thank you for your interest... V 무슨 그림이냐고요? * \|/ * 바로 맨땅에 헤딩하는 그림입죠. \ O / 왠지 사는게 갑갑하게 느껴질때 ============== 한번씩들 해보시라니깐요. hshim@triumph.chem.tamu.edu