1. The cell
Mitochondria : Introduction :
• A single mitochondrion is present in unicellular green alga, Microsterias. Number of mitochondria varies from 50¬–50,000
per cell. Mitochondria of a cell are collectively known as chondriome
. Historical Account :
• C. Benda
(1897) gave the name Mitochondria (Mitos, thread + Chondrion, granules).
• Term ‘Bioplast’ for mitochondria was used by Altman. Ultrastructure :
• Mitochondria are rod shaped organelles, bounded by a double membrane envelope.
• The outer membrane is smooth, the inner membrane surrounds a central cavity of matrix
. Central cavity is filled with jel like substances
• Inner membranes folds are called cristae, these folding are tubular and called microvilli
• Mitochondria contain electron transport systems aggregated into compact structure. F1 particles or oxysome
, tennis racket like bodies on inner membrane involved in oxidation & phosphorylation.
• Kreb’s cycle occurs in mitochondria.
• Each particle is made up of base, stalk and head. Functions of Mitochondria :
• Mitochodria are called power plants
or power houses
or cellular furnaces
• Synthesis of ATP (Adenosine Tri-phosphate)
in mitochondria is called oxidative phosphorylation
• Mitochondria as place of cellular respiration was first observed by Hogeboom.