Lipids, mainly phospholipids, make up the bulk of the cell membrane. how is the structure of the phospholipid so perfectly paired to the function of the cell membrane? a. phospholipids are bulky/large molecules that prevent all molecules from entering/exiting the cell b. the polar tails of the phospholipids provide the barrier between the exterior/interior hydrophilic environments c. lipids contain high energy bonds, and these bonds to provide the energy to move molecules across the membrane d. the head of the phospholipid, which is hydrophilic, to control the movement of large hydrophobic molecules, and the tails of the phospholipid, which are hydrophobic, to control the movement of large hydrophilic molecules