The mitochondria is the location inside the cell where the energy, called adenosine triphosphate, or ATP, is made. This specific part of the cell is composed of rod-shaped organelles. Mitochondria are the animal-version chloroplast, where the energy cycle in plants takes place.
In a normal animal or human cell, there can be anywhere between a thousand and two thousand mitochondria. The energy created by organelle is done through the process of cellular respiration. Every living cell in an organism contains this structure because every living cell plays a role in respiration. Even though these structures are important in the cells, they only range in size between a half and one micrometer. Along with being the main area of energy production, the mitochondria play a part in a number of other functions including cell signaling, growth and cell cycles. The structure has both an inner and outer membrane, which contain a large number of very important proteins. The outer membrane contains proteins called porins, which form channels and let material diffuse from one side of the membrane structure to another. The inner membrane contains around a fifth of the total protein in the mitochondrion structure. The inner membrane does not have porins, which helps makes it impenetrable to other molecules. Along with this, the inner membrane has a phospholipid called cardiolipin which adds another layer of protection to make it even harder for anything to enter the structure that should not be there.