Introduction: Mitochondria are organelles found in eukaryotic cells, which are responsible for generating most of the cell's energy. They are often referred to as the powerhouses of the cell due to their essential role in cellular respiration.

Structure: Mitochondria are enclosed by two membranes, an outer membrane and an inner membrane. The inner membrane is highly folded, forming structures called cristae, which increase the surface area for energy production. The space between the two membranes is called the intermembrane space, while the space inside the inner membrane is called the matrix.

Function: Mitochondria are responsible for generating ATP (adenosine triphosphate), the energy currency of the cell. This process is known as cellular respiration and involves a series of complex biochemical reactions that occur in the mitochondria.

Steps of ATP Production:
1. Glycolysis: This process occurs in the cytoplasm and involves breaking down glucose into pyruvate, which is transported into the mitochondria.
2. Pyruvate oxidation: Pyruvate is converted into acetyl-CoA, which enters the citric acid cycle.
3. Citric acid cycle: This process occurs in the matrix and involves a series of chemical reactions that generate NADH and FADH2, which are electron carriers.
4. Electron transport chain: This process occurs on the inner membrane and involves a series of electron carrier proteins that transport electrons from NADH and FADH2 to oxygen, generating a proton gradient across the inner membrane.
5. ATP synthesis: ATP is generated by the flow of protons back into the matrix through a protein complex called ATP synthase.

Conclusion: In summary, mitochondria are essential for cellular respiration and the generation of ATP, the energy currency of the cell. Their unique structure and function make them critical components of eukaryotic cells and justify their nickname as the powerhouse of the cell.

Mitochondria is known as the powerhouse of the cell because it generates energy which is required for the other cell organelles to work.In the inner membrane of mitochondria there is a space provided for the making of energy molecules called ATP(Adinoscine Triphosphate) which is known as the 'Energy Currency of the Cell'.So, mitochondria is known as the powerhouse of the cell.