Mitochondria are known as the "powerhouses" of the cell because they are really important for making energy. Here’s how they work:

1. Double Membrane:

   • Mitochondria have two layers of membranes. The outer layer is smooth, but the inner layer has folds called cristae. These folds help increase the surface area, making it about five times bigger.

2. Matrix:

   • Inside the mitochondria is a space called the matrix. This area holds special proteins that are important for a process called the Krebs cycle and also contains its own DNA, which helps make proteins.

3. ATP Production:

   • Mitochondria are responsible for making about 95% of a cell's ATP, which is the energy currency for cells. Just one mitochondrion can create around 3 million ATP molecules every minute!

4. Endosymbiotic Theory:

   • Mitochondria look a lot like bacteria. This suggests that they might have come from ancient bacteria a long time ago. This idea is backed up by the fact that they have their own circular DNA, similar to bacteria.

In short, mitochondria are essential for our cells to produce energy and have a fascinating history!