Final answer:
The polarity of a beta sheet depends on the specific amino acids involved, with polar, non-polar, or charged residues determining the overall polarity.
Step-by-step explanation:
The polarity of a beta sheet is dependent on the specific amino acids involved. Beta sheets are secondary structures in proteins that include alternating rows of amino acids lying side-by-side, stabilized by hydrogen bonds. The sidebar chains of amino acids in the beta sheet can vary and may include polar, non-polar, or charged residues. Accordingly, the overall polarity of a beta sheet is determined by the presence and position of these various amino acid side chains. Some amino acids have a propensity to form an alpha helix, while others are more likely to form a beta sheet, and their chemical properties will influence the overall polarity. For example, amino acids with hydrophilic side chains that are exposed to aqueous environments will lend a polar character to the sheet, whereas hydrophobic side chains will increase non-polarity. Therefore, the answer to whether beta sheets are polar or nonpolar is (C) The polarity of a beta sheet depends on the specific amino acids involved.