1. How does the amount of energy stored in glycogen compare to the amount stored as triacylglycerols?

2. What two reasons make glycogen a less efficient energy storage material than triacylglycerols? 3. Why is glycogen such a critical factor in human survival?

(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.