What is the mitochondria?

Mitochondria are small, double-membrane cell organelles that produce energy in the form of ATP. They are found in almost all eukaryotic cells (plants, animals, fungi, and protists). Mitochondria are called “cellular power plants” because they break down glucose and oxygen to release energy. This energy is stored in molecules of adenosine triphosphate (ATP), which is the main energy currency of the cell.

Structure of mitochondria

• Outer membrane: Smooth covering that controls entry and exit of molecules.
• Inner membrane: Folded into structures called cristae, where enzymes for energy production are located.
• Matrix: Fluid inside that contains enzymes, DNA, and ribosomes.
• Cristae: Increase surface area for ATP production.

Key facts

• Mitochondria have their own DNA and ribosomes, so they can produce some of their own proteins.
• They are inherited mostly from the mother.
• They can multiply inside cells when more energy is required.

Mitochondria are essential because no complex organism can live without energy. They link food to usable energy, making life processes possible.