California Cosmetology Written ExamChemical Texture ServicesMedium
During the processing phase of a permanent wave, the reducing lotion chemically changes the hair's disulfide bonds through which process, converting cystine into cysteine?
- AReduction
- BHydrolysis
- COxidation
- DLanthionization
Show answer & explanationAnswer & explanation
Correct answer: A. Reduction
Reduction is the chemical process in which the reducing agent adds hydrogen atoms to the disulfide bonds, converting cystine to cysteine and breaking the bonds so hair can be reshaped.
Why the other options are wrong
- B. Hydrolysis refers to breakdown by water, not the perm reaction.
- C. Oxidation occurs during neutralizing, reforming the bonds afterward.
- D. Lanthionization is specific to hydroxide relaxers, not perms.
Reduction in Perming
The chemical reaction where a reducing agent (e.g., ammonium thioglycolate) adds hydrogen to disulfide bonds, breaking them into two cysteine units.
- Occurs during the processing step of a perm
- Converts cystine into cysteine
- Neutralizer later reverses this through oxidation
Memory trick: 'Reduction adds Hydrogen, like Handing over a gift'