Enzymes facilitate the breakdown of respiratory substrates by lowering the activation energy of reactions, thereby speeding up the biochemical reactions involved in cellular respiration without being consumed in the process.
Option is incorrect because enzymes do not provide energy; they only facilitate reactions that release energy.
Option is incorrect because enzymes are not used as substrates in respiration; they catalyze the breakdown of substrates.
Option is incorrect because enzymes do not transfer energy directly to ATP; they catalyze reactions in which substrates are broken down, and energy is then used to form ATP.