What are some examples of the energetic function of organic molecules?

Since they are complex molecules, presenting many chemical bonds, organic molecules store large amount of energy.

Glucose, for example, is the main energy source for the formation of ATP (adenosine triphosphate), a molecule that is necessary in several metabolic reactions. ATP is an organic molecule too and is itself the energy source for many biochemical reactions. Fat, proteins and some types of organic polymers, like starch and glycogen, that are polymers of glucose, are energy reservoirs for the organism.