During cellular respiration, the coenzymes NAD and FAD help by carrying atoms to the electron transport chain.

high energy

Explanation:

 There are two factors involved in cellular respiration. They are Nicotinamide adenine dinucleotide (NAD+) and flavin adenine dinucleotide (FAD+). They both are in charge of accepting the high-energy electrons and carry them to the electron transport chain. There they used to synthesize ATP molecules.