What are the protein precursors of keratin and in which laye

What are the protein precursors of keratin, and in which layer of the epidermis are they produced?

Solution

Keratohyaline is the main precursor granules that are responsible for the production fo keratin protein in 3-5 cell layers of stratum granulosum. Keratin is a fibrous structural protein that covers the epithelial cells and prevents damage to these cells. Keratin is an important structural component of outer layer of human skin, hair, and nails, tongue, hard palate, which provide necessary toughness to these organs. Keratins assemble to form intermediate filaments that form unmineralized tissues. Epidermis is the outermost layer of the skin made of keratinized stratified squamous epithelial tissue in which outer or apical surface cells are hardened or dead. It does not contain blood vessels (not vascularized), and the dermal layer supplies oxygen and nutrients by means of diffusion. The layer of the epidermis that contains transulacent cells filled keratin are often referred as “thick stratum lucidum”. The other layers often sloughed off from the surface composed of dead cells that are flat and filled with keratin often referred as “stratum corneum”