Mitochondria

Mitochondria

This is a cell organelle present in plant cells and animal cells. Mitochondria word discovered by KOLLIKER .

Mitochondria are absent in broker yards but present in all eukaryotic cells, but in mature and old RCBs of mammalian ,mitochondria are absent.

Mitochondria are the second largest cell organelle.its shape and size depends on the metabolic activities of cell . Average size of mitochondria is 2-6micrometer in length and 0.5 micrometers in diameter.

These cannot be observed by eyes and are visible under light microscope. 

Huge no mitochondria are found in Growing , dividing and metabolically active cells . 

Least number of them are found in yeast , certain green algae and in certain protozoans.Maximum number of mitochondria 50,000 per cell are found in fight muscles of insects .

Structural organisation:

Mitochondria are formed of 2 limiting membranes and 2 chambers.

Mitochondria have semi autonomous nature. these have 70s ribosomes and have ATP molecules to provide energy.

Function of mitochondria 

• Mitochondria are called powerhouse or storage batteries 


• ATP formation through ETC and oxidative phosphorylation.


• Mitochondria of spermatids form middle piece of sperm during sperm Genesis.

Similarities between mitochondria and bacteria

• DNA circular double standard


• Multiple by binary fission 


• Have 70s type of ribosome.


• Mesosomes of bacteria   similar to cristae of mitochondria.