Is it true that phospholipids form the core of all biological membranes?

trueIs it true that phospholipids form the core of all biological membranes?
Yes, the phospholipids are contained in every membrane. The phospholipids have two parts a hydrophobic and hydrophilic (water hating and water loving) part. The hydrophilic parts are on the outside of the membrane and the hydrophilic parts make up the inside, much like a wreath. There are some added proteins for various functions, and some cholesterol to maintain fluidity.Is it true that phospholipids form the core of all biological membranes?
Aye, 'tis true.