Phospholipases are a class of ubiquitous enzymes that have in common their substrate and the fact that they are all esterases. Beyond that, they are a diverse group of enzymes that fall into two broad categories, the acyl hydro lases and the phosphodiesterases. The former group is made up of the phos pholipases Al and A, phospholipase B, and the lysophospholipases. On the 2 other hand, the phosphodiesterases are the phospholipases C and D. The scheme indicates the site of attack of each type of phospholipase. PLA 1 PLB j ft 0 -C-O-C-R d 2 I 1 R-C-0-C-H 0 2 /H2-6-0-U-0-x PLA, 6- '" PLC PLD The...