Energy for you?
The metabolizing of glucose into ATP by oxidative phosphorylation. ATP works by having three unstable phosphate groups attached. These groups contain two negatively charged oxygen's apiece, which repel each other engendering a high energy state. Thus, when one phosphate group is attached to another molecule (phosphorylation ) the other molecule goes through a transformational change and can do cellular work.
In simple words: The sugar (mainly Fructose [other name for "fruit sugar]) is the source of energy.
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them