The amount of phospahtidylinositol-4,5-bisphosphate in the membrane is too small to fill the need for prolonged signaling. What is an alternative source of diacylglycerol? Question 29 options: A. Acetyl CoA B. Cardiolipin C. Intracellular IP2 D. Phosphatidyl choline and ethanolamine E. Triacylglycerols Solution D. Phosphatidyl choline and ethanolamine ..... there is a pthway called phosphatidylcholine pathway of diacyglycerol formation... memory based question no explination.