Answer: Cellular respiration breaks down sugar, and combustion breaks down octane.
Step-by-step explanation:
The cellular respiration is the process by which the molecules of food are broken down in simple components due to the oxidation process resulting in the release of cellular energy in the form of ATP. The cellular respiration involves the oxidation of the fats, carbohydrates (sugars) and proteins which are fuels for the cellular respiration process.
The combustion is also an exothermic reaction just like cellular respiration. The combustion is a process of burning, in this the reactants are reacted with oxygen gas to produce carbon dioxide and water. For example, gasoline is an octane and it burns to produce water and carbon dioxide as products.