Perm solution is applied to break disulfide bonds and soften the ______ structure.

Perm solution is applied to break disulfide bonds and soften the ______ structure.

• A. Protein
• B. Keratin
• C. Lipid
• D. Collagen

Answer: (A)

Breaking disulfide bonds in the hair’s protein structure is what allows the hair to be reshaped. Perm solution reduces the cystine cross-links within the keratin that makes up hair, loosening the strong protein network so you can set it around rods. Since keratin is the protein that forms hair, describing the softened structure as the protein structure is the most accurate way to capture what’s being affected. Lipids aren’t involved in this cross-link chemistry, and collagen isn’t the main hair protein, so they don’t fit the mechanism.

Breaking disulfide bonds in the hair’s protein structure is what allows the hair to be reshaped. Perm solution reduces the cystine cross-links within the keratin that makes up hair, loosening the strong protein network so you can set it around rods. Since keratin is the protein that forms hair, describing the softened structure as the protein structure is the most accurate way to capture what’s being affected. Lipids aren’t involved in this cross-link chemistry, and collagen isn’t the main hair protein, so they don’t fit the mechanism.