NEED HELP!!! what is the difference between a fat cell and a lipid?¿? lipids are said to be molecules! so why are they also called fat cells. cells are only cells when there is cytoplasm, a cell wall, one or more nuclei, and various organelles, all surrounded by a semipermeable cell membrane. how is that we call a lip a cell if its only actually a molecule (a collection of two or more different atoms). ???