Which organelle is known as the powerhouse of the cell?

The mitochondria are known as the powerhouse of the cell because they are responsible for producing adenosine triphosphate (ATP), which is the primary energy carrier in cells. This process, known as cellular respiration, involves the conversion of nutrients, such as glucose, into usable energy. Mitochondria have a unique structure that includes an inner and outer membrane, which creates compartments necessary for efficient energy production. This makes them essential for the high energy demands of many cellular processes.

In contrast, the nucleus serves as the control center of the cell, housing the cell's DNA and coordinating activities such as growth and reproduction. Ribosomes are the sites of protein synthesis, translating genetic information into proteins, but they do not produce energy. The endoplasmic reticulum is involved in the synthesis of proteins and lipids and assists in the transport of materials throughout the cell, but it does not play a direct role in energy production. Therefore, while all these organelles are crucial for various cellular functions, the mitochondria specifically are known for their role in generating the cell's energy, earning them the title of the powerhouse of the cell.