Final answer:
The R groups within the interior of biological membranes would be hydrophobic and nonpolar, as these amino acids are sequestered away from water to maintain the membrane's structure.
Step-by-step explanation:
The R groups of amino acids that are located within the interior of biological membranes would typically have hydrophobic characteristics. These are nonpolar amino acids that do not interact favorably with water. Within the membrane, these hydrophobic R groups are sequestered away from the aqueous environment to maintain the integrity of the membrane's structure. Conversely, polar and charged amino acids are more likely to be found on the surface of membrane proteins, interacting with the aqueous environment inside and outside the cell.
It is important to remember that the chemical nature of the R group determines the chemical nature of the amino acid within the protein, affecting its solubility, and ionization properties. Amino acids can be classified as nonpolar, polar but uncharged, negatively charged, or positively charged based on the chemical nature of their side chains.