When amino acids combine to form the hair’s protein, what configuration do they take?

• A. They form a new amino acid group
• B. They take on a spiralling configuration
• C. The hair's amino acid content will decrease
• D. The hair's amino acid content will increase

Answer: (B)

Amino acids link to form long polypeptide chains that fold into a spiral shape. This spiralling configuration, the hair protein’s common form, is stabilized by hydrogen bonds along the backbone, giving keratin its resilient, wound-up structure. In hair, these helices pack together to create the strong, flexible fibrous protein we know as keratin. The bonding process organizes the existing amino acids into this spiral without creating new amino acids or changing the total amount present, so options about adding or losing amino acids don’t apply.