Final answer:
Complementary surfaces contribute to hydrophobicity by promoting the aggregation of nonpolar regions in molecules, minimizing their interaction with water and affecting molecular folding and structure formation in biological systems.
Step-by-step explanation:
Complementary surfaces contribute to hydrophobicity through the interaction of nonpolar regions in biological molecules. Molecules with hydrophobic side chains, like certain amino acids in proteins, tend to aggregate in aqueous environments, forming hydrophobic interactions. This phenomenon occurs because water molecules form hydrogen bonds with each other, or with other polar groups, rather than with nonpolar hydrophobic groups. The hydrophobic 'R' groups are, therefore, driven to associate with each other, away from the water. This contributes to the three-dimensional folding of proteins, where the hydrophobic amino acid residues are often found in the interior, minimizing their interaction with water. This interaction is also crucial in the formation of structures like the β-sheet peptides that have distinct hydrophilic and hydrophobic surfaces, leading to the creation of nanofiber scaffolds with applications in biomedical engineering.