Hydrostatic weighing

Hydrophobic Interactions are a type of non-covalent bond that occurs when hydrophobic (water-repelling) molecules group together to avoid water molecules. This interaction plays a crucial role in various biological processes, including the formation of cell membranes and the folding of proteins.

Overview

Hydrophobic interactions are caused by the entropy increase that occurs when hydrophobic molecules move away from water molecules and cause the water molecules to become more disordered. This is due to the fact that water molecules form an ordered "cage" around the hydrophobic molecules, and when these molecules move away, the water molecules are free to move more randomly, increasing entropy.

Role in Biological Processes

Hydrophobic interactions play a significant role in the formation of cell membranes. The cell membrane is composed of a bilayer of phospholipids, which have a hydrophilic (water-attracting) head and a hydrophobic tail. The hydrophobic tails group together to avoid water, forming the bilayer structure.

In addition, hydrophobic interactions are crucial in the folding of proteins. Proteins are composed of amino acids, some of which are hydrophobic. In an aqueous environment, these hydrophobic amino acids group together in the interior of the protein, causing the protein to fold into a specific shape.

Hydrophobic Effect

The hydrophobic effect refers to the observed tendency of nonpolar substances to aggregate in an aqueous solution and exclude water molecules. This effect is a fundamental aspect of hydrophobic interactions and is a major driving force behind protein folding, membrane formation, and emulsion stability.

See Also

• Hydrophilic Interactions
• Van der Waals Forces
• Hydrogen Bonding
• Lipid Bilayer
• Protein Folding