Glycogen grams of glucose are present in the blood of humans at all times; in fasted individuals, blood glucose is maintained constant at this level at the expense of glycogen stores in the liver and skeletal muscle. Glycogen stores in skeletal muscle serve as a form of energy storage for the muscle itself; however, the breakdown of muscle glycogen impedes muscle glucose uptake, thereby increasing the amount of blood glucose available for use in other tissues. Liver glycogen stores serve as a store of glucose for use throughout the body, particularly the central nervous system. The human brain consumes approximately 60%
Glycogen branching enzyme bulkier substrate such as branched sugar. Through primary structure analysis and the x-ray crystallographic structures of the members of the α-amylase family, seven residue were conserved, Asp335, His340, Arg403, Asp 405, Glu458, His525, and Asp526 (E coli. numbering). These residues are implicated in catalysis and substrate binding. Glycogen binding enzymes in other organisms have also been crystallized and structurally determined, demonstrating both similarity and variation to GBE found in Escherichia coli. In glycogen, every 10 to 14 glucose units, a side branch with an additional chain of glucose units occurs. The side chain attaches at carbon atom 6 of a