Which organelle is known as the powerhouse of the cell?

The mitochondria are referred to as the powerhouse of the cell because they play a crucial role in producing adenosine triphosphate (ATP), the primary energy currency of the cell. Through the process of cellular respiration, mitochondria convert biochemical energy from nutrients into ATP, which is then used to fuel various cellular processes. This organelle has its own DNA and double membrane, which further highlights its unique role in energy production and suggests an evolutionary history as an independent prokaryotic cell that was engulfed by an ancestral eukaryotic cell.

In contrast, the nucleus serves as the control center of the cell, housing genetic material and coordinating activities such as growth, metabolism, and reproduction. Ribosomes are involved in protein synthesis, translating mRNA into polypeptides, while the endoplasmic reticulum (ER) is primarily responsible for the synthesis and folding of proteins (rough ER) and lipid production (smooth ER). These functions, while essential for cellular function, do not focus on energy production in the manner that mitochondria do.