Hair wave patterns: Curly vs Straight

Why is hair straight or curly?

Each hair fiber is made up of coils composed of coils composed of coils down to the molecular structure of amino acids that form keratin chains. Cysteine, an amino acid that has a high content of sulphur atoms, is responsible for strong disulfide bonds. If the disulfide bonds are attached to adjacent and level molecules, they form a ladder-like bridge and the hair fiber will be straight.  If the bonds are formed between diagonal cysteine amino acids, this bends the bridge and forms curly hair fibers.


Why does my curly hair become straight when it becomes wet?

Hair fibers also form weak hydrogen bonds between amino acids.  These bonds can be temporarily or permanently broken. Water can temporarily break hydrogen bonds which is why curly hair becomes straight when wet. These bonds reform when hydrogen-rich water is removed.


Why do roller setting and curling irons curl my hair?

After water breaks these bonds, new bonds can be formed with heat or persistent positioning of the hair such as roller setting the hair or using flat irons, blow dryers, and curling irons.  These bonds can be permanently broken and reformed with chemical processes including relaxing systems (relaxers) and permanent wave systems (perms).


facebooktwittergoogle_pluslinkedinmailPosted on: January 19, 2015, by : DrHillHairLoss

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