Question

What substances that primarily comprise plasma membranes form a bilayer?

Answer 1

phospholipids

Plasma membranes are primarily made up of phospholipids  orange . The hydrophilic  "water-loving"  head and two hydrophobic  "water-hating"  tails are shown. The phospholipids form a bilayer  two layers . The middle of the bilayer is an area without water. There can be water on either side of the bilayer. There are many proteins throughout the membrane.