MITOCHONDRIA
Mitochondria are important organelles of eukaryotic cells. They manufacture and supply energy to the cell. Therefore they are also called powerhouse of the cell.
Mitochondria are particularly abundant in metabolically active cells, tissues such (is muscle and tissues involved in active transport.
Size
The size (0.5 – 1.5 µn wide) and number of mitochondria varies and depend upon the physiological activity of the cell.
Functions
- Under compound microscope mitochondria may be rod shaped, vesicles or filaments. In Electron Microscope, Mitochondria have two membranes, outer smooth and inner with cristae.
- The inner surface of cristae in the mitochondrial matrix has small knob like structures called F1 particles. These are involved in ATP formation.
- Mitochondrial matrix contains enzymes, coenzymes and organic and inorganic salts. Mitochondria also contain DNA and ribosomes.
- Mitochondrial matrix helps in metabolic processes like Kerb's cycle, aerobic respiration and fatty acid metabolism etc. Their main function is to make ATP via the process of aerobic respiration. ATP diffuses into the cell and provides instant chemical energy.
- Mitochondria have a double membrane; the outer membrane is smooth while the inner one is folded. This arrangement gives as large internal surface area on which the complex reactions of aerobic respiration can take place. Mitochondrion is a self-replicating organelle.