Discuss the main structure of hair being keratin. The structure of keratin as a fibrous, structural protein, insoluble in water and organic solvents. Keratin is also structurally found in nails, skin, and horns of many animals. Hair consists of 3 sections; the medulla or innermost part, the cortex , or middle highly structured part, and the cuticle,or outer layer containing lipids. The difference between the follicle, hair shaft and root bulb was summarized and diagrammed. Texture of hair consisting of curl pattern, volume, and consistency was discussed in detail for all 3. The shape of the follicle and the circumference determining the texture, volume, and consistency. The chemistry of hair lightening, using bleach to oxidize the melanin to colorless without changing the color of the keratin, which remains pale yellow. Hydrogen peroxide in alkaline solution is used, with the decomposition of peroxide to produce oxygen being the chemical reaction. The chemistry of permanent hair coloring, the use of ammonia to open the cuticle and the depositing of the color in the cortex was the final step in hair coloring.