In the stable form of a protein, the nonpolar (hydrophobic) side chains of amino acids are generally oriented toward the interior of the protein molecule. This arrangement minimizes their exposure to the aqueous environment, as hydrophobic side chains tend to cluster together inside the protein to avoid contact with water. Conversely, polar side chains are typically oriented toward the exterior, where they can interact with the surrounding water molecules through hydrogen bonding. This distribution of polar and nonpolar amino acids is a key factor in protein folding and stability