<prompt> PI P2 is cleaved into IP3 and DAG by -Protein kinaseCPhospholipasecAMPCaspases  <response>: Ans. is b i.e., Phospholipase o Activation of phospholipase by stimulatory G protein hydrolyses the membrane phospholipid phosphatidyl inositol 4, 5 bisphosphate PIP2 to generate the second messenger inositol 1, 4, 5 - triphosphate IP3 and diacylglycerol DAG.o IP3 mobilizes Ca2 from intracellular organelles - increased cytosolic Ca2.o DAG enhances Protein Kinase c activation by Ca2.o Ca2 acts as third messenger in this type of transduce mechanism and mediates the physiological effects of drugs. 