<span>Chemically straightening hair changes the shape of disulfide bonds, which alpha keratin protein; this is the second protein structure. However, as the hair continues to grow out, this keratin protein grows with it, thus outlasting the effects of the chemicals which change the shape of the protein. </span>
The cell membrane is a selectively permeable membrane which controls what goes in and out to ensure that not just anything comes in through it's own accord.
