What molecules do organism use to store energy

Glycogen and triglycerides

Living organisms employ two main kinds of energy storage. Energy-rich molecules such as glycogen and triglycerides stock energy in the formation of covalent chemical bonds. Cells integrate such molecules and store them for the later discharge of the energy.

the endomembrane system i think

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.