The reactive contributes to the ability of aldehydes and ketones to be involved in energy reactions.

The reactive CARBONYL GROUP, contributes to the ability of aldehydes and ketones to be involved in energy reactions. Aldehydes and ketones undergo different types of reactions that lead to various products. One example of these reactions are nucloephilic reactions which lead to the production of alcohols, alkenes, diols, imine, etc.

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.