Why do phospholipids form of bilayer in water?

A. The phosphate portions repel each other

B. The hydrophilic and hydrophobic parts attract each other

C. The phosphate portions attract water, and the lipid portions repel water

D. The lipid portions attract water, and the phosphate portions repel water

The answer is C. The phosphate portions attract water, and the lipid portions repel water.

This is because the phosphate portions are negatively charged, hence making it polar and hydrophilic. On the other hand, the lipid portions are uncharged and nonpolar, hence making it hydrophobic.

The right answer is C.

A lipid bilayer, or lipid bilayer, is a thin polar membrane consisting of two layers of lipid molecules.

The outer region on each side of the lipid bilayer is constituted by the hydrophilic heads of the lipids (phosphate group). This region is fully hydrated. The inner region is the hydrophobic core (long fatty acid chains), the water molecules cannot access.