Chemistry of Chemical Hair straightener?

can someone please tell me the chemical make up of relaxers? thanksChemistry of Chemical Hair straightener?
Hair has the amino acid cysteine. Cysteine, for short, is Cys-SH. The -SH mercapto sulfhydryl bonds oxidize to form cystine, Cys-S-S-Cys. It is the -S-S- bonds that hold hair as ';curly,'; ';straight,'; ';kinky,'; or whatever. A reducing agent in the straightener, usually a sulfide, reduces the Cys-S-S-Cys bond to Cys-SH, allowing the treatment to relax hair. When the hair is relaxed and in the form that the stylist wants, an oxidizing agent restores the -S-S- bonds between neighboring Cys.Chemistry of Chemical Hair straightener?
Something to do with the alkali breaking the keratin bonds.