Which cell organelle is known as the powerhouse of the cell?

The mitochondria are often referred to as the "powerhouse of the cell" because they are the primary site of adenosine triphosphate (ATP) production through the process of cellular respiration. They convert the energy stored in glucose and other nutrients into ATP, which serves as a vital energy currency for nearly all cellular processes. The structure of mitochondria, characterized by their double membrane and folds known as cristae, plays a crucial role in facilitating the chemical reactions necessary for producing ATP. This unique design increases the surface area available for these reactions, leading to efficient energy production.

In contrast, the nucleus is primarily involved in storing genetic information and regulating gene expression, ribosomes are responsible for protein synthesis, and the Golgi apparatus functions in modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles. While each of these organelles has essential roles in cellular function, the specific association of mitochondria with energy production is what earns them the title of the powerhouse of the cell.