Chitin Chitin Chitin (CHON) ( ), a long-chain polymer of "N"-acetylglucosamine, is a derivative of glucose. It is a primary component of cell walls in fungi, the exoskeletons of arthropods, such as crustaceans (e.g., crabs, lobsters and shrimps) and insects, the radulae of molluscs, cephalopod beaks, and the scales of fish and lissamphibians. The structure of chitin is comparable to another polysaccharide - cellulose, forming crystalline nanofibrils or whiskers. In terms of function, it may be compared to the protein keratin. Chitin has proved useful for several medicinal, industrial and biotechnological purposes. The English word "chitin" comes from the French word
Natural killer cell memory, fundamental for responding to secondary infections with the same antigen. The role of NK cells in both the innate and adaptive immune responses is becoming increasingly important in research using NK cell activity as a potential cancer therapy. NK cell receptors can also be differentiated based on function. NK Cells are not a subset of the T lymphocyte family. Natural cytotoxicity receptors directly induce apoptosis after binding to Fas ligand that directly indicate infection of a cell. The MHC-dependent receptors (described above) use an alternate pathway to induce apoptosis in infected cells. Natural killer cell activation is determined by