What is mitochondria, its parts and function??

  Introduction to Mitochondria.

 

Fig:-Structure of mitochondria. 

Mitochondria is rod shaped or oval shaped structure present in the cytoplasm of both plant and animal cell. Its diameter is 0.5 to 5 micron. It contains DNA. It is double membrane cell organelle .it's inner layer is folded to for finger like structure called Cristae which increase surface area of cell respiration.The cavity of cristae is called the intercristae space ,and is continuous with the inner membrane space.On the matrix side of inner membrane, associated with it, there are several thousand small tennis-racket like small particles known as elementary particles or F1- particle or oxysomes. Each elementary particle consists of a head piece, stalk and base. Elementary particles are involved in the process of oxidation and phosphorylation reactions.

In the head of F particles, enzyme ATPase or ATP synthetase is present which controls synthesis of ATP. so these are also called ATP particles and are the functional units of mitochondria. Chemical composition of mitochondria varies in different animal and plant cells. However, they are found to contain protein (65-70%), lipids (25-30), RNA (0.5%) and small amount of DNA.

# Functions  of  Mitochondria

1. It contains energy rich molecules like ATP(Adenosine Triphosphate), ADP(Adenosine Diphosphate) which provide energy  to the body and helps in different biochemical reactions and cellular respiration hence it is called as "powerhouse of cell."
2. It helps in the synthesis of amino acids.
3. It helps in the formation of protein.
4. It helps in the synthesis of fatty acids.
5. It helps in the formation of lipids.
6. It helps in Kreb's cycle.

Note:-Kreb's cycle means the formation of Pyruvic acid from glucose molecule.

# Origin of Mitochondria.

-->Mitochondria are self-duplicating organelles due to the presence of DNA molecule(mitochondrial DNA) So new mitochondria always formed by growth and division of pre-existing mitochondrion.