Final answer:
NADH and FADH are important molecules in cellular respiration, carrying high-energy electrons. They are used in the electron transport chain to generate ATP.
Step-by-step explanation:
NADH and FADH are important molecules in cellular respiration. They are produced during the breakdown of glucose in the citric acid cycle and carry high-energy electrons. These electrons are then passed along the electron transport chain in the mitochondria, where their energy is used to generate ATP, the main energy currency of cells.