The hair is made by cells, each of which contains macrofibrillas packaged. These microfribillas are form by keratine. There are two types of keratine : alpha and beta, which are differentiated by their structure and components. Keratine type is inextensible, unlike keratine type alpha, this last type is found among others in hair; but there is the possibility to transform the alpha keratine in beta keratine by appliying heat, MORE.....