Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense?

Question

Quizplus · Accepted Answer

The two back-to-back phospholipid layers with the polar heads facing out on both sides is called a phospholipid bilayer and is the most common arrangement found in cell membranes. This is because the polar heads of the phospholipids interact with the polar water molecules on both the inside and outside of the cell, while the non-polar tails interact with each other in the middle of the membrane, creating a barrier that separates the cell from its environment.

Phospholipids Make Up Most of the Lipid Part of the Cell