In the context of chemical hair texturing, which bond is primarily targeted to change curl pattern?

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

Answer: (A)

Disulfide bonds are the ones primarily targeted. Hair curl pattern owes much of its shape to covalent links between cysteine residues in keratin. When a chemical texturizer uses a reducing agent, those disulfide bonds are broken, allowing the hair to be reshaped into a new form. After shaping, an oxidizing step reforms the bonds in the new configuration, locking in the altered curl. Hydrogen bonds, by comparison, are much weaker and readily swap with moisture, providing temporary shape rather than a permanent change. Ionic bonds (salt bridges) are also influenced by pH but don’t produce the long-lasting curl change the disulfide bonds create. Peptide bonds are the protein backbone links and aren’t targeted to reconfigure curl because breaking them would damage the hair rather than safely alter its pattern.