Hydrophobic Interactions
Water molecules are cohesive because they are polar molecules. Since oil molecules are non polar, they are neither repelled nor attracted to each other.
When drops of oil are added to water, the drops combine to form a larger drop, as the cohesion of the water molecules forces the oil drops to come together.
Hydrophobic interaction is the appearance of avoiding water.
Hydrophobic and hydrophilic interactions help determine the 3D shape of biologically important molecules and structures such as proteins and cell membranes.
Self assembly
Protein and cell membrane molecules automatically organize themselves into more complex and biologically useful structures, when put in water.
