Hair: Straight or Curly?

HAIR: STRAIGHT OR CURLY?

Hair is made up of a protein known as keratin. Keratin contains an unusually large number of cysteine residues (about 8%), which give it many disulfide bridges to maintain its three dimensional structure. People can alter the structure of their hair (if they feel it is either too straight or too curly) by changing the location of these disulfide bridges. This is complished by first applying a reducing agent to the hair to reduce all the disulfide bridges in the protein strands. Then the hair is given the desired shape (using curlers to curl it or combing it straight to uncurl it), and an oxidizing agent is applied that forms new disulfide bridges. The new disulfide bridges maintain the hair's new shape. When this treatment is applied to straight hair, it is called a "perinanent." It is called "hair straightening" when it is applied to curly hair.