Answer:What part of the amino acid contributes to the hydrophobic behavior of a region of the polypeptide?":
The hydrophobic behavior of a region of the polypeptide is primarily influenced by the presence of nonpolar amino acids with bulky side chains, such as alanine, valine, leucine, isoleucine, phenylalanine, and tryptophan. These nonpolar side chains do not interact with water molecules and instead fold away from water to minimize contact with the polar environment.