Final answer:
Phospholipids are the main component of cell membranes, forming a bilayer structure. They contain a hydrophilic head and a hydrophobic tail.
Step-by-step explanation:
The main component of cell membranes is phospholipids. Phospholipids are lipids that contain a phosphate group and are a major component of cell membranes in all living things.
They have a hydrophilic head and a hydrophobic tail, which allows them to form a bilayer structure in cell membranes. This bilayer structure helps regulate the flow of substances into and out of the cell.