Mitochondria - one of the most important components of any cell.They are called chondriosomes.It granulovidnye or filamentous organelles that are an integral part of the cytoplasm of plants and animals.They are the producers of ATP molecules, which are so necessary for many processes in the cell.
What are mitochondria?
Mitochondria - a power base of the cells, their activity is based on the oxidation of organic compounds and the use of energy liberated by the decay of ATP molecules.Biologists in plain language it is called a power generation station for kletok.V 1850 mitochondria found in the form of granules in the muscle.Their numbers varied depending on growth conditions: they accumulate more in those cells where a large oxygen deficit.This happens most often during exercise.In these tissues appears an acute shortage of energy, which make up the mitochondria.
emergence of the term and in the theory symbiogenesis
Bend in 1897 first introduced the concept "mitochondria", to denote granular and filamentous structure in the cell cytoplasm.In shape and size they are diverse: a thickness of 0.6 mm, length - from 1 to 11 microns.In rare situations, the mitochondria may be large and branched node.
symbiogenesis In theory, given a clear idea of what the mitochondria and how they appeared in the cells.It says that there chondriosomes defeat in bacterial cells, prokaryotes.Since they could not independently apply oxygen to produce energy, it prevented their full development, and progenote could develop smoothly.During the evolution of the relationship between them made it possible to pass on their genes progenote now eukaryotes.Due to this progress mitochondria are no longer independent organisms.Their gene pool can not be implemented in full, as is its partial blockage of enzymes, which are in any cell.
Where do they live?
mitochondria are concentrated in those regions of the cytoplasm, where there is a need for ATP.For example, in the muscle tissue of the heart, they are located far away from the myofibrils, and sperm form a protective masking around the axis of the harness.There they produce a lot of energy to the "tail" cool.In this way, the sperm moves toward the egg.
new mitochondria in the cells formed by a simple division of the preceding organelles.During his entire genetic information is stored.
Mitochondria: how they look
The shape of mitochondria resembles a cylinder.They are common in eukaryotes, occupying from 10 to 21% of the cell volume.Their shapes and sizes vary greatly, and can vary depending on the conditions, but the width is constant: 0.5-1 microns.Chondriosomes movements depend on the places where the cells to make quick waste of energy.Moves in the cytoplasm using the structure for movement tsitoskeleta.Zamenoy different in size mitochondria, working separately from each other and supply energy to some areas of the cytoplasm, are long and branched mitochondrion.They are able to provide energy portions cells located far from each other.Such collaboration chondriosomes observed not only in single-celled organisms, but in multicellular.The most complex structure chondriosomes found in mammalian skeletal muscle, where the largest branched chondriosomes are joined to each other using mezhmitohondrialnye contact (CMI).
They are narrow gaps between adjacent to each other mitochondrial membranes.This space has a high electron density.MMK longer found in heart muscle cells, which are associated with the operating chondriosomes.
To better understand the issue, it is necessary briefly to paint the importance of mitochondria, the structure and function of these organelles amazing.
how they work?
to understand what the mitochondria, it is necessary to know their structure.This unusual source of energy is a sphere, but more elongated.The two membranes are close to each other:
- external (smooth);
- inner which forms a leaf-shaped outgrowths (crista) and tubular (tubules) form.
If you do not take into account the size and shape of mitochondria structure and function is the same.Chondriosomes delimited by two membranes, the size of 6 nm.The outer membrane of mitochondria resembles a container that protects them from hyaloplasm.The inner membrane of the outer portion otedinyaet width 11-19 nm.Distinguishing feature of the inner membrane is considered to be its ability to protrude inside the mitochondria, taking the form of flattened ridges.
internal cavity fills mitochondria matrix which has a fine grained structure wherein yarns sometimes exhibit and granules (15-20 nm).Filaments matrix organelles create DNA molecules and small size granules - mitochondrial ribosomes.
ATP synthesis in the first stage takes place in hyaloplasm.At this stage there is initial oxidation of substrates or glucose to pyruvic acid.These procedures take place without oxygen - anaerobic oxidation.The next stage of energy production is aerobic oxidation and decomposition of ATP, the process takes place in the mitochondria of cells.
What are mitochondria?
The main functions of the organelles are:
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generation of energy for the cells;
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storage of genetic information in the form of its own DNA.
presence in the mitochondria of their deoxyribonucleic acid once again confirms the symbiotic theory of the emergence of these organelles.Also, in addition to the basic work, they are involved in the synthesis of amino acids and hormones.
Mitochondrial pathology
mutations that occur in the genome of the mitochondria, leading to frustrating consequences.The carrier of genetic information is a human DNA, which is passed from parents to offspring, and the mitochondrial genome is transmitted only from the mother.This fact is explained very simply: the cytoplasm of prisoners it chondriosomes children get along with the woman's egg, the sperm are absent.Women with this deviation can be passed on to offspring mitochondrial disease, a sick man - no.
chondriosomes Under normal circumstances, a copy of the same DNA - gomoplazmiya.In the genome mitochondria mutations can occur as a result of co-existence of healthy and mutated cells occurs heteroplasmy.
Thanks to modern medicine so far identified more than 200 diseases, which served as the reason of occurrence of mutation of mitochondrial DNA.Not in all cases, but the maintenance of therapeutic and treatment of mitochondrial diseases lend themselves well.
So we dealt with the question of what the mitochondria.Like all other organelles, they are very important for the cell.They indirectly take part in all the processes, which need energy.
