Which bond is most directly affected during permanent waving, creating potential for curl pattern change?

Which bond is most directly affected during permanent waving, creating potential for curl pattern change?

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

Answer: (B)

Permanent waving targets the disulfide bonds in the hair’s keratin. These covalent cross-links between cysteine units hold the curl pattern in place. The waving process uses a reducing agent to break those S-S bonds, allowing the hair to be reshaped around rods. Then an oxidizing step reforms the bonds in new positions, setting a new curl. Because disulfide bonds are what lock the curve into a lasting form, they are the bonds most directly involved in creating a potential curl pattern change. Hydrogen bonds and salt bonds can influence how hair holds moisture and respond to heat, so they play a role in temporary shape, but they are easily reversible with changes in humidity, water, or pH and do not create a lasting curl. Peptide bonds form the protein backbone of keratin and are not broken or reformed during waving; altering them would damage the hair rather than create the desired curl.

Permanent waving targets the disulfide bonds in the hair’s keratin. These covalent cross-links between cysteine units hold the curl pattern in place. The waving process uses a reducing agent to break those S-S bonds, allowing the hair to be reshaped around rods. Then an oxidizing step reforms the bonds in new positions, setting a new curl. Because disulfide bonds are what lock the curve into a lasting form, they are the bonds most directly involved in creating a potential curl pattern change.

Hydrogen bonds and salt bonds can influence how hair holds moisture and respond to heat, so they play a role in temporary shape, but they are easily reversible with changes in humidity, water, or pH and do not create a lasting curl. Peptide bonds form the protein backbone of keratin and are not broken or reformed during waving; altering them would damage the hair rather than create the desired curl.