Which organelle is the powerhouse of the cell, converting glucose into ATP energy?

• A. Mitochondria
• B. Nucleus
• C. Chloroplast
• D. Ribosome

Answer: (A)

The main idea is where a cell turns glucose into usable energy as ATP. This happens mostly in the mitochondria, the cell’s energy factories. During cellular respiration, glucose is processed through pathways that deliver electrons to the inner mitochondrial membrane, where the electron transport chain and ATP synthase use the resulting proton gradient to generate ATP. The inner membrane folds (cristae) increase surface area, making these energy-producing reactions more efficient. Other organelles serve different roles—the nucleus houses DNA, chloroplasts in plants capture light energy to drive photosynthesis, and ribosomes make proteins—so the mitochondrion is the best answer for turning glucose into ATP.