<prompt> In the human body, the action of surfactant is done by-Sugar saltSoap waterLipid and proteinBase and lipid  <response>: Ans. is c i.e lipid and protein Approximate composition of a surfactantComponentPercentage compositionDipalmitoyl PhosphatidylcholineDPPC62Phosphatidylglycerol5Other phospholipids10Neutral lipids13Proteins8Carbohydrate2DPPC and PG are types of phospholipids.Thus surfactant is made up of lipids and protein and carbohydrate.Surfactant action by a molecule requires it to be amphipathic i.e. it should have both a polar group and a non polar chain; such a combination is possessed by lipids phospholipids proteins. 