Phospholipases are enzymes that can catalyze cleavage of acyl or phosphoacyl moieties from glycerophospholipids, as shown in Figure 19.6. Phospholipases are implicated in rearrangement of phospholipids after they have been synthesized and in release of arachidonic acid from glycerophospholipids in eicosanoid metabolism.

Phospholipase A2 cleaves an acyl group from glycerophospholipids (Figure 19.6) and may be involved in synthesis of lung surfactant, which contains a saturated fatty acid at position 2, unlike normal glycerophospholipids, which contain an unsaturated fatty acid.