Which organelle is known as the powerhouse of the cell?

The mitochondria are known as the powerhouse of the cell because they are the primary site of ATP (adenosine triphosphate) production through the process of cellular respiration. This process involves the conversion of biochemical energy from nutrients into ATP, which is used by the cell as a direct energy source to fuel various cellular activities. The inner membrane of the mitochondria contains proteins that facilitate the electron transport chain and ATP synthesis, making it crucial for energy metabolism in aerobic organisms.

While other organelles have important functions—such as the nucleus housing genetic material, chloroplasts being responsible for photosynthesis in plant cells, and lysosomes containing digestive enzymes for waste processing—they do not play the central role in energy production that the mitochondria do. Thus, the designation of mitochondria as the powerhouse reflects their essential role in energy conversion and maintenance of cellular functions.