Introduction
The mitochondria powerhouse of the cell. It is a semi-autonomous cellular organelle that generates ATP which are the energy-rich compounds and are the main factors of the cell’s basic function.
What is Mitochondria?
Mitochondria is a double membrane-bound structure that is difficult to locate in a cell and requires a specific stain. Detail structure of mitochondria can only be seen under electron microscopy. The number of mitochondria per cell depends upon the functions and activity. There are mainly two types of shapes of mitochondria namely cylindrical and sausage-shaped (Diameter 0.2-0.2 micrometer and length of 1.0-4.1 micrometer).
Origin
Mitochondria contain their genome, an indication that they are derived from bacteria through endosymbiosis. However, the ancestral endosymbiont genome has lost most of its genes so the mitochondrial genome (mitogenome) is one of the most reduced genomes across organisms.
Mitochondria: Structure
- Mitochondria has two membranes outer and inner therefore has two aqueous compartments. The inner membrane forms many infoldings to increase the surface area called cristae.
- Both membranes have their own set of enzymes that actively participate in different functions.
- The inner compartment has a uniform or homogeneous substance called the matrix.
- Matrix helps in protein synthesis and, therefore, has singular DNA molecules, RNA molecules, and ribosomes.
Mitochondria reproduction
The organelle mitochondria reproduce mainly by binary fission similar to bacteria. The division pattern is different in both single-cell and multicell organisms. In a single-cell organism, the division is like a cell cycle where each daughter cell receives a single mitochondrion. In a multicellular organism, mitochondria may replicate their DNA and divide mainly in response to the energy needs of the cell, rather than in phase with the cell cycle.
Mitochondria Function
- Mitochondria produces cellular energy in the form of ATP thus mitochondria are the powerhouse of the cell.
- The matrix of mitochondria helps in the synthesis of proteins.
- It also helps in cellular respiration.
- It also, produces NADH and GTP in the citric acid cycle and also synthesizes the heme group and iron-sulfur cluster. It also produces phospholipid which is an important component of the cell membrane.
- Mitochondria play an important role in human health and dysfunction in mitochondria results in several maternal inherited diseases.
Diseases related to mitochondria
Many diseases like neurological disorders like autism, dysfunction of muscles like muscle weakness and myopathy, and diabetes are the major diseases related to dysfunctional mitochondria. Mitochondria functions are also directly related to aging. It was found that aging cells have relatively fewer cristae and are bound to only the membranes whereas in young cells the cristae protrude deep into the matrix. This may indicate that aging is directly proportional to ATP synthesis and thus mitochondria play a major role.
