Mitochondria By-Dr. P. B. Sirsat Assist.Professor in Zoology, B.Sc.F.Y.

Mitochondria The mitochondria are found in plant and animal cells. Mitochondria are bounded by a double membrane surrounding fluid-filled matrix.

The mitochondria are found in plant and animal cells. Mitochondria are bounded by a double membrane surrounding fluid-filled matrix.

Organelles and evolution Both chloroplasts and mitochondria are double membrane bound They involved in energy reactions They contain extranuclear DNA and characteristic small ribosomes of their own This has led biologists to believe that there may be some similarity in their origins in the cells of eukaryotes. The endosymbiotic theory

MITOCHONDRION The inner membrane contains the enzyme necessary for the synthesis of Adenosine Triphosphate (ATP) The mitochondria are closely associated with the pathways of respiration These metabolic pathways are divided up and supported by the membranes

The inner membranes of mitochondria are cristae . The matrix contains enzymes that break down carbohydrates and the cristae house protein complexes that produce ATP.

The mitochondrial matrix contains lipids,protein,circular DNA and 70-S ribosomes. The mitochondrial crestae shows a layers of protein molecules and lipid molecules. The creaste also shows respiratory chain enzymes and F1 particles called alimentary particles. FUNCTIONS OF MITOCHONDRIA It performs function such as oxidation, oxidative photophosporylation and respiratory chain enzymes. It is actually respiratory organ of cells where the food stuff i.e. carbohydrate, fat are complementary, oxidize in to the CO2 and H2O & large amount of energy is released which is utilized by mitochondria for the synthesis ATP . Therefore mitochondria is known as ‘powerhouse of cell’. REACTION: A-P~P~P ------ ADP+Pi+7000 Cal .

Mitochondrial Structure (cont.)

Mitochondrial Structure

Mitochondrial Structure (cont.) SUBSARCOLEMMAL MITOCHONDRIA MITOCHONDRIA MODELED CAPILLARY INTERFIBRILLAR MITOCHONDRIA

MITOCHONDRION (pl. mitochondria) outer membrane inner membrane Mitochondrial envelope Inter membrane space Cristae Inner matrix 1.0 to 12.5 µm

MITOCHONDRION (gk mitos = thread khondrion = granule) TEM of mitochondrion from mouse kidney cell

Mitochondrion structure