Mitochondria are the 'powerhouses' of the eukaryotic cell. These organelles are the sites of cellular respiration, the metabolic process that generates energy from carbohydrates in the cell. The energy produced is in the form of ATP, the energy carrier molecule.
Mitochondria are physically adapted to this task:
- Double membrane: The outer membrane controls entry and exit of material into the organelle. The inner membrane is folded to form structures called the cristae:
- Cristae: shelf-like extensions of the inner membrane. They have a large surface area for enzymes that carry out reactions in respiration to attach to.
- Matrix : the material that fills space inside the inner membrane of the mitochondria. It contains protein, lipids and traces of DNA so that mitochondria can produce their own proteins. Enzymes involved in respiration are also contained within the matrix.