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 1-phosphate is that the very polar phosphorylated glucose cannot leave the cell membrane and so is marked for intracellular catabolism. Phosphoglucomutase-1 deficiency is known as glycogen storage disease type 14 (GSD XIV). In glycogenesis, free glucose 1-phosphate can also react with UTP to form UDP-glucose, by using the enzyme UDP-glucose pyrophosphorylase. It can then return to the greater glycogen structure via glycogen synthase. β-Glucose 1-phosphate is found in some microbes. It is produced by inverting α-glucan phosphorylases including maltose phosphorylase, kojibiose phosphorylase and trehalose phosphorylase and is then converted into glucose 6-phosphate by β-phosphoglucomutase. Glucose 1-phosphate Glucose 1-phosphate (also called cori