Biology

The macromolecule that makes up the majority of cell membranes is B.phospholipids.

Phospholipids form the phospholipid bilayer, which serves as the basic structural framework of cell membranes. This bilayer consists of two layers of phospholipids, with their hydrophobic (water-repelling) tails facing inward and their hydrophilic (water-attracting) heads facing outward, towards the water inside and outside the cell.