<prompt> Second messenger is produced from:PhosphatidylinositolPhosphatidylserinePhosphatidylcholineNone  <response>: Ans. A. PhosphatidylinositolRef: Harper 31e page 202PhosphatidylinositolPhosphatidylinositol presents in the cell membrane.The inositol is present as its stereoisomer, myoinositol.Plays an important role in cell signaling and membrane trafficking.Phosphatidyl inositol is a precursor of second messenger in hormonal pathways.Action of Phospholipase C on Phosphatidyl Inositol 4,5 Bisphosphate PiP2 Diacyl Glycerol and Inositol Tris phosphate IP3 are formed and both act as second messengers. 