Which of the following is the primary purpose of cellular respiration in eukaryotic cells?

• A. To produce oxygen from carbon dioxide
• B. To synthesize glucose from sunlight
• C. To break down ATP into glucose
• D. To convert glucose into usable ATP energy

Answer: (D)

Verified step by step guidance

1. Understand the concept of cellular respiration: Cellular respiration is a metabolic process in eukaryotic cells that converts glucose into usable energy in the form of ATP (adenosine triphosphate). This process occurs in the mitochondria and involves multiple stages, including glycolysis, the citric acid cycle, and oxidative phosphorylation.
2. Eliminate incorrect options: Review the provided choices and eliminate those that do not align with the purpose of cellular respiration. For example, 'To produce oxygen from carbon dioxide' is incorrect because cellular respiration consumes oxygen and produces carbon dioxide as a byproduct. Similarly, 'To synthesize glucose from sunlight' is incorrect because this describes photosynthesis, not cellular respiration. Lastly, 'To break down ATP into glucose' is incorrect because ATP is the product of cellular respiration, not the starting material.
3. Focus on the correct option: The correct answer is 'To convert glucose into usable ATP energy.' Cellular respiration begins with glucose, which is broken down through a series of enzymatic reactions to produce ATP, the energy currency of the cell.
4. Relate the process to energy production: Explain that ATP is essential for cellular functions, such as muscle contraction, active transport, and biochemical reactions. Cellular respiration ensures that eukaryotic cells have a continuous supply of ATP to meet their energy demands.
5. Summarize the importance of cellular respiration: Highlight that cellular respiration is a fundamental process for energy production in eukaryotic cells, enabling them to perform vital functions and maintain homeostasis.