What type of molecule makes up the majority of the cell membrane?

The majority of the cell membrane is composed of phospholipids, which form a bilayer that provides structural integrity and fluidity. These molecules have hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails, allowing them to arrange themselves in a way that creates a barrier between the inside and outside of the cell. Embedded within this bilayer are proteins, cholesterol, and carbohydrates, which contribute to various functions such as signaling and transport.