Which part of the cell is known as the power plant?

The mitochondria are often referred to as the "power plants" of the cell because they play a crucial role in energy production. These organelles are responsible for generating adenosine triphosphate (ATP), the energy currency of the cell, through a process called cellular respiration. This energy is essential for various cellular functions, including muscle contraction, cell division, and active transport.

Mitochondria convert nutrients, primarily glucose, into ATP by using oxygen and generating carbon dioxide as a byproduct. Their distinct double membrane structure, with the inner membrane folded into cristae, increases the surface area for biochemical reactions, making them highly efficient at producing energy.

In contrast, the nucleus houses the cell's genetic material and coordinates activities such as growth and reproduction but is not involved in energy production. The cytoplasm contains various organelles and is the site of many metabolic processes, but it does not specifically generate energy. Ribosomes are responsible for synthesizing proteins and do not play any role in energy production. Thus, the function of mitochondria in energy generation firmly establishes them as the cell's power plant.