Final answer:
The functionality of membranes is determined by their proteins and their amphiphilic structure, characterized by a bilayer of phospholipids, with hydrophilic heads and hydrophobic tails, where phospholipids are the most common lipids and glycolipid head groups comprise carbohydrates.
Step-by-step explanation:
The specialized functions of different membranes are largely determined by the proteins they contain. Membrane lipids are amphiphilic molecules, composed of a hydrophilic portion and a hydrophobic portion. All cell membranes have the same bilayer structure, with the hydrophilic heads of the phospholipids facing into the interior of the membrane and the hydrophobic tails on the outside. The most common lipids in most cell membranes are the phospholipids. The head group of a glycolipid is composed of carbohydrates.