Delaware Cosmetology and Barbering Practice Exam

Which type of bond is primarily broken during the process of perming?

1. Hydrogen bonds

2. Covalent bonds

3. Disulfide bonds

4. Ionic bonds

The correct answer is: Disulfide bonds

The process of perming primarily focuses on altering the structure of hair through the manipulation of its bonds. Disulfide bonds are key to maintaining the hair's natural curl and wave pattern, as they link the sulfur atoms of cysteine amino acids within the hair structure. During a perm procedure, hair is treated with a chemical solution that breaks these disulfide bonds. Once these bonds are broken, the hair can be shaped into a new form, typically using curlers or rods. After the hair is shaped, a neutralizing solution is applied, which reforms the disulfide bonds in the new configuration, effectively setting the hair into a curled or waved style that is designed to last for a period of time. While hydrogen bonds also play a role in hair’s structure, they are weaker and more easily broken through processes like water exposure or heat application. Covalent bonds represent a stronger type of bond that contributes to the hair's structure fundamentally but are not the primary targets in perming. Ionic bonds also have minimal involvement in the perming process. Thus, the focus on disulfide bonds is what enables the transformative effect characteristic of a perm.