A hydrate is different from other chemical compounds because it has water molecules loosely attached to it. These certain water molecules can be be removed by a heating process known as dehydration. Hydrates sometimes involves ionic compounds and transition metals to act as the cation.
(1) the yield from the complete oxidation of glycogen is about 4kcal/g in contrast with about 9kcal/g. Consequently a gram of nearly anhydrous triacyglycerol stores more than six times as much energy as a gram of hydrated glycogen.
(2) (i) glycogen is hydrated
(ii) glycogen are polar
(3) glycogen is an energy reserve that can be quickly mobilized to meet sudden needs and represent the major energy store of the brain.