Which chemical bonds are broken during the perming process?

During the perming process, the primary chemical bonds that are broken are disulfide bonds. Disulfide bonds are strong covalent bonds that occur between the sulfur atoms of cysteine amino acids in the keratin of hair. These bonds give hair its strength and structure. The perming process involves the application of a chemical solution that breaks these disulfide bonds, allowing the hair to be reshaped into curls or waves.

Once the disulfide bonds are broken, the hair can be set into a new shape with the help of rods and a neutralizing solution, which re-forms the disulfide bonds in their new configuration after the hair is shaped. This process is fundamental to achieving the desired texture and style in perming, making the breaking of disulfide bonds a crucial step in altering the hair structure.

The other types of bonds mentioned, like ionic bonds, covalent bonds (excluding disulfide), and hydrogen bonds, play different roles in hair's overall structure but are not specifically targeted during the perming process as disulfide bonds are.