Gourt > Science > Biology > Cell Biology > Organelles > Mitochondrion
In cell biology, a mitochondrion (plural mitochondria) (from Greek mitos thread + khondrion granule) is an organelle, variants of which are found in most eukaryotic cells. Mitochondria are sometimes described as "cellular power plants," because they convert organic materials into energy in the form of ATP via the process of oxidative phosphorylation. Usually a cell has hundreds or thousands of mitochondria, which can occupy up to 25% of the cell's cytoplasm. Mitochondria have their own DNA and according to the endosymbiotic theory may have descended from free-living prokaryotes that were closely related to rickettsia bacteria.
Mitochondrion structure
A mitochondrion contains outer and inner membranes composed of phospholipid bilayers and proteins. The two membranes, however, have very different properties. Inside the mitochondria is a compartment called the matrix that contains both proteins and DNA.
The outer membrane
The outer mitochondrial membrane, which encloses the entire organelle, has a protein-to-phospholipid ratio similar to the eucaryotic plasma membrane (about 1:1 by weight). It contains numerous integral proteins called porins, which contain a relatively large internal channel (about 2-3 nm) that is permeable to all molecules of 5000 daltons or less. Larger molecules can only traverse the outer membrane by active transport. It also contains a variety of enzymes involved in such diverse activities as the elongation of fatty acids, oxidation of epinephrine (adrenaline), and the degradation of tryptophan.The inner membrane
The inner mitochondrial membrane contains proteins with four types of functions:- Those that carry out the oxidation reactions of the respiratory chain.
- ATP synthase, which makes ATP in the matrix.
- Specific transport proteins that regulate the passage of metabolites into and out of the matrix.
- Protein import machinery.
Love it! RT@RobinShen @kelsponies See => http://mitochondrion.tumblr.com/post/282276801/we-are-not-cat-dependent
kelsponies (Kelly L.) Tue, 15 Dec 2009 03:46:48 -0000
Love it! RT@RobinShen @kelsponies See => http://mitochondrion.tumblr.com/post/282276801/we-are-not-cat-dependent
@kelsponies See => http://mitochondrion.tumblr.com/post/282276801/we-are-not-cat-dependent
RobinShen (Robin Shen) Tue, 15 Dec 2009 03:44:20 -0000
@kelsponies See => http://mitochondrion.tumblr.com/post/282276801/we-are-not-cat-dependent
Photo: mitochondrion: Well Im not anyway. http://tumblr.com/xdw4o2bi4
RobinShen (Robin Shen) Sun, 13 Dec 2009 23:10:57 -0000
Photo: mitochondrion: Well Im not anyway. http://tumblr.com/xdw4o2bi4
Photo: mitochondrion: Science is rad. Science FTW http://tumblr.com/xkw4nici6
savagemike (ãã¤ã¯ ã®ãã½ã³) Sun, 13 Dec 2009 07:02:35 -0000
Photo: mitochondrion: Science is rad. Science FTW http://tumblr.com/xkw4nici6
na over use na ang mitochondrion ng mga cells ko..it's because of too much release of Adenosine Triphosphate. ... http://plurk.com/p/2ycjqi
hanasaionji26 (hanasaionji) Sat, 12 Dec 2009 07:21:42 -0000
na over use na ang mitochondrion ng mga cells ko..it's because of too much release of Adenosine Triphosphate. ... http://plurk.com/p/2ycjqi
Photo: mitochondrion: Bunny thief! http://tumblr.com/xdw4maw5q
RobinShen (Robin Shen) Fri, 11 Dec 2009 21:06:18 -0000
Photo: mitochondrion: Bunny thief! http://tumblr.com/xdw4maw5q
Cellular Respiration - Overview of biochemistry of energy conversion within the organelle, as part of Kimball's Biology Pages.
Mitochondria Interest Group - Schedule of meetings, seminars, including archive, membership list, joining details and related links, maintained at NIH, Bethesda, MD.
Mitochondria Lectures - Study guides to accompany graduate lectures, with links to related topics by Gwen V. Childs, at Little Rock, AR.
Mitochondria Research Society - History, related diseases, publications, meetings, postdoctoral positions, membership, executive board profiles and international contacts.
Mitochondrion - Peer-reviewed international research journal. Includes PDF sample issue, submission and subscription details from Elsevier BV, The Netherlands.
MITOP - Project for mitochondria-related genes, proteins and diseases, with database searchable by species; human, mouse, yeast, C.elegans and N.crassa. Maintained in Munich, Germany.
The Mitochondrial Website - Genetics, biochemistry and functions of mitochondria in cell life, in diseases, apoptosis to death, in English and French.
Meta Description: [ description of mitochondrial functions in cellular life and death.
Description des fontions de la mitochondrie dans la cellule. ]
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