Mitochondria (Singular : Mitochondrion)


Mitochondrion is known as the power house of the cell. It plays significant role in aerobic respiration Mitochondria are absent in prokaryotic cells and red blood corpuscles (RBCs).

The structure of mitochondrion:
 i. Shape of the mitochondria may be oval or spherical or like spiral strip.

ii. It is a double membrane bound organelle. i. Outer membrane is permeable to various metabolites due to presence of a protein-Porin or Parson's particles.

IV. Inner membrane is selectively permeable to few substances Both membranes are separated by intermembrane space. only.

vi. Inner membrane shows several finger like or plate like folds called as cristae which bears numerous particles oxysomes & cytochromes/electron carrier.

vii. Inner membrane encloses a cavity called inner chamber, containing a fluid-matrix. viii. Matrix contains few coils of circular DNA, RNA, 70S types of ribosomes, lipids and various enzymes of Krebs' cycle and other pathways.


Inner membrane of mitochondria bears numerous particles - Oxysomes (F1-F0 / Fernandez - Moran / Elementary particles /mitochondrial particles). Each particle consists of head and stalk / foot. Head (F1)/ lollipop head faces towards matrix and foot (F0) is embedded in inner membrane. Head acts as an enzyme ATP synthase and foot as proton channel. Oxysomes are involved in proton pumping and ATP synthesis.

Comments

Post a Comment

Popular posts from this blog

Structure of myosin & actin filaments.

Image
i. Myosin filament: a. Each myosin filament is a polymerized protein. Many meromyosins (monomeric proteins) i constitute one thick filament. b. Myosin molecule consists of two heavy chains (heavy meromyosin / HMM) coiled around each other forming a double helix. One end of each of these chains is projected outwardly is known as cross bridge . This end folds to form a globular protein mass called myosin head . c. Two light chains are associated with each head forming 4 light chains/light meromyosin / LMM. d. Myosin head has a special ATPase activity . It can split ATP to produce energy. e. Myosin contributes 55% of muscle proteins. f. In sarcomere, myosin tails are arranged to point towards the centre of the sarcomere and the heads point to the sides of the myofilament band. ii. Actin filament : It is a complex type of contractile protein. It is made up of three components: a. F actin : It forms the backbone of actin filament. F actin is made up of two helica
Read more

test blog

Image
Table of content:  1. Plants 2. Animals 3. Humans 4.  Gods Plant Plants   are the   eukaryotes   that form the   kingdom   Plantae ; they are predominantly   photosynthetic . This means that they obtain their energy from   sunlight , using   chloroplasts   derived from   endosymbiosis   with   cyanobacteria   to produce   sugars   from   carbon dioxide   and water, using the green pigment   chlorophyll . Exceptions are   parasitic plants   that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Animal Historically, as in  Aristotle's biology , the plant kingdom encompassed all living things that were not  animals , and included  algae  and  fungi . Definitions have narrowed since then; current definitions exclude the fungi and some of the algae. By the definition used in this article, plants form the  clade   Viridiplantae  (green plants), which consists of the  green algae  and the  embryophytes  or land plants ( hornworts ,
Read more