Natural fiber exoskeletons of insects and arthropods. In shells and exoskeletons, the chitin fibers contribute to their hierarchical structure. In nature, pure chitin (100% acetylation) does not exist. It instead exists as a copolymer with chitin's deacetylated derivative, chitosan. When the acetylized composition of the copolymer is over 50% acetylated it is chitin. This copolymer of chitin and chitosan is a random or block copolymer. Chitosan is a deacetylated derivative of chitin. When the acetylized composition of the copolymer is below 50% it is chitosan. Chitosan is a semicrystalline “polymer of β-(1-4)-2-amino-2-deoxy-D-glucose”. One difference between chitin and chitosan is that chitosan is
Glucose 6-phosphatase a highly conserved residue that completely destroyed G6PT activity. These mutations lead to the prevalence of GSD-1 by preventing the transport of glucose-6-phosphate (G6P) into the luminal portion of the ER and also inhibiting the conversion of G6P into glucose to be used by the cell. The third type of glucose-6-phosphatase deficiency, glucose-6-phosphatase-β deficiency, is characterized by a congenital neutropenia syndrome in which neutrophils exhibit enhanced endoplasmic reticulum (ER) stress, increased apoptosis, impaired energy homeostasis, and impaired functionality. It can also lead to cardiac and urogenital malformations. This third class of deficiency is also affected by a G6PT deficiency as