Why is cellular respiration considered a catabolic reaction?

• A. It breaks down glucose into simpler molecules, releasing energy.
• B. It involves the formation of complex molecules from simpler ones.
• C. It converts light energy into chemical energy stored in glucose.
• D. It synthesizes glucose from simpler molecules, storing energy.

Answer: (A)

Verified step by step guidance

1. Understand the definition of catabolic reactions: Catabolic reactions are processes that break down complex molecules into simpler ones, releasing energy in the process.
2. Identify the main function of cellular respiration: Cellular respiration is a metabolic pathway that breaks down glucose into simpler molecules, such as carbon dioxide and water, while releasing energy in the form of ATP.
3. Compare cellular respiration to the characteristics of catabolic reactions: Since cellular respiration involves the breakdown of glucose, it aligns with the definition of a catabolic reaction.
4. Consider the energy aspect: Cellular respiration releases energy, which is a key feature of catabolic reactions, as they typically release energy stored in chemical bonds.
5. Evaluate the options given in the problem: The correct answer is the one that describes cellular respiration as breaking down glucose into simpler molecules, releasing energy, which matches the characteristics of a catabolic reaction.