The mitochondria are a group of organelles within the cell, and are responsible for the energy production in the cell. Their inner membrane has numerous folds and layered structures known as cristae. These help to increase the surface area of the organelle. In addition to the membrane, the mitochondrial matrix consists of a mixture of proteins and enzymes, as well as inorganic ions, nucleotide cofactors, and organic molecules. The enzymes present within the matrix play a vital role in the synthesis of ATP molecules.
Function
The mitochondria are tiny organelles within cells that produce energy from various sources. They are composed of an inner membrane and an outer membrane, which are both made of phospholipids. Porins are present on the outer membrane. Porins help the mitochondria move larger proteins across the outer membrane. In addition to generating energy, mitochondria are also involved in calcium signaling, stress responses, and cellular signaling hubs. Because of this, mitochondria play an important role in human health. They are also deeply implicated in ageing and apoptosis.
Mitochondria are small organelles that are between 0.75 and three micrometers in diameter. They have two membranes – the outer membrane is permeable to small molecules, while the inner membrane only allows a few small molecules to pass. Inside the inner membrane, proteins involved in the electron transport chain and other chemical reactions are located.
The number of mitochondria in a cell varies, depending on its metabolic requirements. Some cells have as few as one large mitochondrion and others may contain thousands of smaller organelles. Mitochondria are found in nearly all eukaryotes, including humans and animals. Their size makes them easy to observe with a light microscope. They were discovered in the 1800s and were given the name mitochondria from the Greek words for thread and granule. For many years after their discovery, mitochondria were thought to be a means of transmitting hereditary information.
Structure
Scientists have found that the structure of mitochondria, the powerhouse of the cell, influences the growth and function of cancer cells. In some cancers, an abnormal rate of mitochondrial fission is the cause. Knocking down the process of mitochondrial replication inhibits tumour growth.
The structure of mitochondria is a complex web of membranes. The outer membrane is permeable to small molecules and contains special channels to transport large molecules. The inner membrane is less permeable and allows only a small number of molecules to pass. The inner membrane is composed of a matrix containing the mitochondrial genome DNA and enzymes involved in the tricarboxylic acid cycle (CAT), also known as the Krebs cycle.
In addition to their role as the cell’s powerhouse, mitochondria have many other functions. They participate in apoptosis, synthesize the molecules necessary for DNA, and serve as calcium ion buffers. This structure makes mitochondria a central player in disease research.
As the “powerhouse of the cell,” mitochondria produce ATP, the energy currency of the cell. They also regulate cellular metabolism through a series of reactions. These reactions include the citric acid cycle and oxidative phosphorylation.
Disorders
There are several disorders of mitochondria in the cell. Most of these disorders are hereditary, and the disease is more common in muscle cells than in other cells. These cells use more energy than other cells, so they are prone to these conditions. The DNA responsible for these disorders is inherited from the mother. They can also be triggered by toxins or medicines. The most common organs affected by these diseases are the brain, liver, and skeletal muscle.
Because mitochondria are present in every cell, disorders of mitochondria can affect multiple organ systems. As a result, symptoms of these disorders vary considerably, and they are often difficult to diagnose. The symptoms of these disorders may be similar to those of other diseases, and they can be mild, moderate, or severe, depending on where in the body they affect. Some of the most common symptoms of mitochondrial diseases are seizures, fatigue, gastrointestinal disorders, and visual and hearing problems. Some patients may also develop diabetes, heart failure, or kidney failure.
The symptoms of mitochondrial disease depend on how many mitochondria are damage. Some people experience a variety of symptoms, from a slowing down of brain function to significant developmental delay. In severe cases, mitochondrial disease can cause seizures, difficulty with walking, and heart and kidney problems. The treatment for mitochondrial disease will depend on the specific symptoms, and may include physical therapy, vitamins, special diets, and medicines.
Endosymbiosis
Mitochondria are a crucial part of an eukaryotic cell, generating energy in the form of ATP, which powers the cell. However, mitochondria didn’t always exist in eukaryotes. They originally evolved from a prokaryotic organism called an archaea. The bacterial cell eventually learned to live in the archaea as an endosymbiotic organism, or a host that possesses the characteristics of the mitochondria.
During the evolution of life on Earth, oxygenation began to provide oxygen, enabling eukaryotes to evolve. These organisms then used the energy produced by oxygen respiration to power their mitochondria. These organelles, also known as mitochondria, are the powerhouse of the cell and originate from bacteria. In-fact, the two types of organisms share very close symbiotic relationships.
In addition to generating ATP, mitochondria also play an important role in cellular metabolism. In eukaryotes, these tiny organelles are responsible for converting the most useful energy from carbohydrates and fatty acids into ATP, the currency of energy. These processes take place in the mitochondria, which are oval-shape and have two membranes. The inner membrane contains many protrusions called cristae.
Autogenous theory
While autogenous mitochondria have thought to have originate in prokaryotes, the ‘autogenic’ hypothesis claims that mitochondria derive from a protozoan endosymbiont. This theory has drawn criticism from biologists who believe in the evolution of mitochondria via micromutation and gene duplication.
The ‘autogenous’ hypothesis is consistent with diverse aspects of eukaryotic cell biology, and it has link to a hypothesis called the Cavalier-Smith hypothesis. This theory contends that mitochondria originated in archaea, and that this trait became widespread throughout the archaea. It further asserts that the mitochondria evolved in an archaeal symbiotic association, which gave rise to haloarchaea.
However, there are several major issues associate with the Autogenous mitochondria theory. The complexity of the mitochondrial cenancestor indicates that it involves in a complicated metabolic association. Some researchers believe that it was an intracellular parasite, or perhaps it was a periplasmic predator. But there are also some questions that have yet to answer.
To answer these questions, it is important to look at mitochondrial biology from a molecular level. The mitochondria are essential double-membrane compartments that supply the energy necessary for aerobic respiration. The first step in aerobic respiration involves the oxidation of pyruvate, a nutrient that then converts to CO2. The second step is the synthesis of ATP from carbon dioxide and oxygen.
Symptoms
The symptoms of mitochondrial dysfunction vary greatly from person to person and there is no single consensus on what causes this disorder. Diagnosis is often make by examining a combination of signs and symptoms along with appropriate laboratory tests. Parents should keep a log of all their child’s symptoms, recording both the frequency and severity of the symptoms. It is especially important to note that non-verbal children can exhibit a different range of symptoms.
The condition can cause by environmental and genetic factors. The mitochondria are particularly susceptible to oxidative damage and nutrient deficiencies. Free radicals, also known as reactive oxygen species, are a major cause of oxidative stress. Increasing the levels of “helper molecules” in the body can reduce the likelihood of developing mitochondrial dysfunction. A healthy mitochondria is essential to optimal health and disease prevention. Although many symptoms are common, some are more serious and can require treatment.
Symptoms of mitochondrial dysfunction can vary from person to person and can even be different in family members. They also depend on the organ system affected by the disorder. Typically, mitochondrial dysfunction affects organs that require energy. Common symptoms include muscle weakness, poor growth, seizures, and fatigue. The condition may also lead to developmental delays or autism.
