Discuss the structure and functions of mitochondria.

Structure of mitochondria: Mitochondria are tiny bodies of varying shapes and size, found in the cytoplasm. Each mitochondrion is covered by a double-membrane envelope. Outer membrane is smooth and porous while inner membrane is projected with finger-like structures, the cristae. These cristae create a large surface area for ATP-generating chemical reactions. The cristae as well as inner membrane possess small tent like particles called F1 particles or oxysomes.

The cavity of mitochondria is filled with matrix. The mitochondrial matrix contains lipids, proteins, circular DNA and RNA.

Functions of mitochondria:

(i) Mitochondria is the site of cellular respiration or oxidation of food in a cell.

(ii) The energy, released in the form of ATP, is used by body cells to synthesise new chemical compounds and to carry out other metabolic activities.