Question

20. Explain the hydrophobic effect. Why do we refer to the hydrophobic effect, and not the hydrophobic bond?

Answer 1

The hydrophobic effect is the obsereved tendency of nonpolar substances to aggregte in queous solution and exclude water molecules. This occurs because interaction between the hydrophobic molecules enable the displaced water molecules to make hydrogen bonds more freely with each other and increase the number of hydrogen bonds they are involved with, thereby decreasing the overall free energy. The word hydrophobic literally means "water-fearing' and it describes the segregation and apparent repulsion between water and nonpolar substances.

The hydrophobic effect is responsible for the seperation of a mixture of oil and water into it two components. The hydrophobic effect is also responsible for the stability and fusion of cell membranes and vesicles, is and importaant factor driving protein folding as well as the insertion of membrane proteins into the nonpolar lipid environment and finally contributes to the stability of protein - small molecule associations. Hence the hydrophobic effect is essentioal to life. Substances for which this effect is observed are known as hydrophobes.