Answer:
Keratinization and cornification are both processes by which epithelial cells become hardened and flattened, but they differ in their specific context and characteristics.
Keratinization refers to the process by which cells in the epidermis of the skin become keratinized or filled with the protein keratin. This process occurs as cells in the lower layers of the epidermis divide and migrate upward, undergoing various changes in cell structure and protein synthesis. Eventually, the cells flatten and die, forming a layer of dead cells that provide a protective barrier against the external environment. Keratinization is a continuous process that occurs throughout the life of the skin.
Cornification, on the other hand, is a specific type of keratinization that occurs in specialized epithelial cells called corneocytes. These cells are found in the outermost layer of the skin, the stratum corneum, and are responsible for providing the main barrier function of the skin. During cornification, the corneocytes undergo a complex process of protein synthesis and modification, resulting in the formation of a tough, impermeable layer of cells. Unlike keratinization, cornification is a terminal differentiation process, meaning that the cells are no longer able to divide or perform other cellular functions.