How does the lipid portion help maintain water concentration on each side of the bilateral?

Explanation:The phospholipid bilayer formed by these interactions makes a good barrier between the interior and exterior of the cell, because water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane. Can water cross the plasma membrane at all?

It also helps the cell move things in and out. The cell membrane is made of what is called a phospholipid bilayer, which means it has two layers of phospholipids. ... This allows the phosphates to be exposed to water, either in the cell or the environment, while the lipids are protected from water Lipids are essential for all life on Earth. They play many important roles in maintaining the health of an organism. Arguably the most important function lipids perform is as the building blocks of cellular membranes. Other functions include energy storage, insulation, cellular communication and protection.Large quantities of water molecules constantly move across cell membranes by simple diffusion, often facilitated by movement through membrane proteins, including aquaporins. In general, net movement of water into or out of cells is negligible.

the answer is:

carbon dioxide