Enzymes are the catalysts which make possible biochemical reactions.
Consider that bichemistry takes place at about 37 degrees C in water and contrast that to typical reaction conditions in organic chemistry. Enzymes called lipases do the same thing at body temperature in minutes. Without enzymes, our body chemistry would not occur, and life would not exist. This illustrates the impressive power of enzymes as catalysts. Remember that catalysts increase the rate of a reaction, but are not themselves consumed or produced by the reaction.