In aqueous solutions, globular proteins usually turn their polar groups outward toward the aqueous solvent, and their nonpolar groups inward, away from the polar molecules. This is because the nonpolar groups prefer to interact with each other, and exclude water from these regions. These interactions are called hydrophobic, meaning water-hating, interactions. Hydrophobic interactions are usually weaker than hydrogen bonding, and act over large surface areas.

Both alcohols and ethers with up to three or four carbons are soluble in water because the OH groups in these molecules form hydrogen bonds with the water molecules. Alcohols and ethers having higher molecular weights do not dissolve well in water, however, because the water molecules can not completely surround those molecules. The molecule 1-heptanol, for example, consists of an alkyl chain of seven carbons and an OH group. The OH group forms hydrogen bonds with water molecules, but the...