Which bonds does the waving lotion break to allow rearrangement of the hair's curl?

Which bonds does the waving lotion break to allow rearrangement of the hair's curl?

• A. Disulfide bonds
• B. Hydrogen bonds
• C. Peptide bonds
• D. Ionic bonds

Answer: (A)

The hair’s curl is rearranged by breaking the disulfide bonds in the keratin. The reducing agents in waving lotion break these strong cross-links between cysteine residues, turning them into two sulfhydryl groups so the hair can be reshaped around rods. After wrapping, a neutralizer re-forms new disulfide bonds in the new configuration, locking in the curl. Hydrogen bonds and ionic bonds are weaker and mainly affect moisture and pH, so they don’t provide the permanent rearrangement. Peptide bonds form the protein backbone and aren’t the bonds targeted in a typical perm.

The hair’s curl is rearranged by breaking the disulfide bonds in the keratin. The reducing agents in waving lotion break these strong cross-links between cysteine residues, turning them into two sulfhydryl groups so the hair can be reshaped around rods. After wrapping, a neutralizer re-forms new disulfide bonds in the new configuration, locking in the curl. Hydrogen bonds and ionic bonds are weaker and mainly affect moisture and pH, so they don’t provide the permanent rearrangement. Peptide bonds form the protein backbone and aren’t the bonds targeted in a typical perm.