Which of the following is an endergonic process?

• A. Photosynthesis
• B. Combustion of glucose
• C. Rusting of iron
• D. Respiration

Answer: (A)

Verified step by step guidance

1. Understand the concept of an endergonic process: An endergonic process is a chemical reaction that requires energy input to proceed. It is characterized by a positive change in Gibbs free energy (ΔG > 0).
2. Identify the processes given in the problem: Photosynthesis, Combustion of glucose, Rusting of iron, and Respiration.
3. Analyze each process: Photosynthesis is the process by which plants convert light energy into chemical energy, storing it in the form of glucose. This process requires energy input from sunlight, making it endergonic.
4. Consider the other processes: Combustion of glucose, Rusting of iron, and Respiration are exergonic processes, meaning they release energy (ΔG < 0).
5. Conclude that Photosynthesis is the only endergonic process among the options provided, as it requires energy input to convert carbon dioxide and water into glucose and oxygen.