Question

What is mitochondria and what is its functions in plants and animals?

Answer 1

Mitochondria is a membrane bound cellular structure and is found in most of the eukaryotic cells. The mitochondria ranges from 0.5 to 1.0 micrometer in diameter. The mitochondria are sometimes described as power plants of the cells. These organelles generate most of the energy of the cell in the form of adenosine triphosphate (ATP) and it is used a source of chemical energy. The mitochondria also involved in other cellular activities like signaling, cellular differentiation, cell senescence and also control of cell cycle and cell growth. Mitochondria also affect human health, like mitochondrial disorder and cardiac dysfunction and they also play important role in the aging process. The term 'mitochondrion' is derived from a Greek word 'mitos' which means 'thread' and 'chondrion'which means 'granule'.

Functions of mitochondria depends on the cell type in which they are present.

• The most important function of the mitochondria is to produce energy. The simpler molecules of nutrition are sent to the mitochondria to be processed and to produce charged molecules. These charged molecules combine with oxygen and produce ATP molecules. This process is known as oxidative phosphorylation.
• Mitochondria help the cells to maintain proper concentration of calcium ions within the compartments of the cell.
• The mitochondria also help in building certain parts of blood and hormones like testosterone and estrogen.
• The liver cells mitochondria have enzymes that detoxify ammonia.
• The mitochondria also play important role in the process of apoptosis or programmed cell death. Abnormal death of cells due to the dysfunction of mitochondria can affect the function of organ.

Plant Cell Mitochondria
Like in other eukaryotic cells, the mitochondria in plants play an important role in the production of ATP via the process of oxidative phosphorylation. Mitochondria also play essential roles in other aspects of plant development and performance. It also has various properties which allows the mitochondria to interact with special features of metabolism in plant cell. Animal Cell Mitochondria
Mitochondria are known as "power houses" of the cells, they are unusual organelles and are surrounded by a double membrane. These organelles have their own small genome. They divide independently by simple fission. The division of the mitochondria is a result of the energy demand, so the cells with high need of energy have greater number of mitochondria . The process creating energy for the cell is known as cellular respiration. Most of the chemical reactions of this process happen in the mitochondria.

A typical animal cell may have about 1000 to 2000 mitochondria.