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

A mitochondrion is the human cell organelle commonly known as the powerhouse of the cell.

Mitochondria generate much of a cell’s usable chemical energy in the form of ATP through aerobic cellular respiration. Nutrients are broken down through pathways including the citric acid cycle, and electrons pass through the inner-membrane electron transport chain. The resulting proton gradient drives ATP synthase, which produces ATP.

Mitochondria are surrounded by two membranes. Their inner membrane is folded into structures called cristae, increasing the surface available for energy-producing reactions. They also contain their own small, circular DNA and ribosomes, a clue supporting the endosymbiotic theory that mitochondria evolved from bacteria living inside an ancestral cell.

The phrase “powerhouse” is useful but incomplete. Mitochondria also help regulate programmed cell death, calcium balance, and metabolism. Some human cells, including mature red blood cells, have no mitochondria, while cells with high energy demands, such as heart muscle cells, contain many.