(i) It was first observed by A. Kolliker (1880). Altmann (1894) named it as Bioplasts. Later Benda (1897, 1898), named as mitochondria. They are ovoid, rounded, rod shape and pleomorphic structures.
(ii) Mitochondrion consists of double membrane, the outer and inner membrane.
(iii) The outer membrane is smooth, highly permeable to small molecules and it contains proteins called Porins, which form channels that allows free diffusion of than about 1000 daltons and the inner membrane divides the membrane divides the mitochondrion into two veen two membranes and the inner chamber filled with matrix.
(iv) The inner membrane is convoluted (infoldings), called convoluted (infoldings), called crista (plural: cristae). Cristae contain most of the enzymes for electron transport system.
(v) Inner chamber of the mitochondrion is filled with pro the mitochondrion is filled with proteinaceous material called mitochondrial matrix.
(vi) The inner membrane consists of stalked particles called elementary particles or Fernandez Moran particles, F1 particles or Oxysomes.
(vii) Each particle consists of a base, stem and a round head. In the head ATP synthase is present for oxidative phosphorylation.
(viii) Inner membrane is impermeable to most ions, small molecules and maintains the proton gradient that drives oxidative phosphorylation.
(ix) Mitochondria contain 73% of proteins, 25-30% of lipids, 5-7 % of RNA, DNA (in traces) and enzymes (about 60 types).
(x) Mitochondria are called Power house of a cell, as they produce energy rich ATP.
(xi) All the enzymes of Kreb.s cycle are found in the matrix except succinate dehydrogenase.Mitochondria consist of circular DNA and 70S ribosome.
(xii) They multiply by fission and replicates by strand displacement model. Because of the presence of DNA it is semi-autonomous organelle.
(xiii) Unique characteristic of mitochondria is that they are inherited from female parent only. Mitochondrial DNA comparisons are used to trace human origins.
(xiv) Mitochondrial DNA is used to track and date recent evolutionary time because it mutates 5 to 10 time faster than DNA in the nucleus.
