The best means of defence is attack ENZYNES 

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If you are a beetle and about to be eaten by a predator such as a spider or a frog, how do you escape? Bombardier beetles have evolved a spectacularly successful strategy (Figure 3.1). It makes use of the fantastic speeds of enzyme-controlled reactions. When threatened by a predator, the beetle uses the extended tip of its abdomen to squirt a boiling hot chemical spray at its attacker.

 

The release of the spray is accompanied by a loud popping sound. The beetle can swivel the tip of the abdomen to spray accurately in almost any direction. With the potential predator reeling from this surprise attack, the beetle makes good its escape.

How are enzymes involved? Inside the beetle’s abdomen is a chemical mixing chamber into which hydrogen peroxide and hydroquinone are released.

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The chamber contains two enzymes, catalase and peroxidase, which make the reactions they catalyse proceed several million times faster than normal. Hydrogen peroxide is broken down into oxygen and water and the oxygen is used to oxidise the hydroquinone into quinone. The reactions are violent and release a great deal of heat, vaporising about 20% of the resulting liquid. Within a fraction of a second a boiling, foul-smelling gas and liquid mix is explosively discharged through an outlet valve.