As we have discussed the nucleus in detail, now we are going to discuss about mitochondria another organelle present in the Eukaryotic cell and it is called powerhouse of a cell as we have discussed earlier that cell is the basic Structural and functional unit of an organism. So to keep a cell in living state, cell needs energy and this energy is generated by mitochondria.
Mitochondria- power house of a cell
Mitochondria is a double membrane bound organelle which is present in all Eukaryotic cells. It has two membranes one the outer membrane which is present outside and another is inner membrane which is present inside and forms number of in folding called cristae. These cristae increase the surface area for several enzyme action.Inner membrane of mitochondria is made up of many phospholipids bilayer, cardiolipin is one of the major phospholipids that make up the inner mitochondrial membrane. It is involved in various processes within the mitochondria, including electron transport chain, oxidative phosphorylation, and ATP synthesis. Cardiolipin's presence in the inner mitochondrial membrane is essential for maintaining the integrity and functionality of this organelle.Cardiolipin interacts with proteins involved in electron transport and ATP synthesis.
Mitochondria is the site of aerobic respiration, due to this aerobic respiration the energy is liberated in the form of ATP and this energy brings out the oxidation of carbohydrate proteins and fats. This ATP is synthesized by and enzyme complex called ATP synthase or oxysomes or F0-F1 particles. These oxysomes are invaginations of inner membrane where enzymatic reactions takes place and due to this reactions ATP is synthesized.
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ATP synthase consists of two main components: the F1 portion, which protrudes into the mitochondrial matrix, and the Fo portion, embedded in the inner mitochondrial membrane.The Fo portion forms a proton channel that allows the flow of protons back into the mitochondrial matrix. As protons flow through the Fo channel, it causes a rotation of the F1 portion. This rotation drives a series of conformational changes in the F1 portion, which facilitates the synthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi).
ATP synthase consists of two main components: the F1 portion, which protrudes into the mitochondrial matrix, and the Fo portion, embedded in the inner mitochondrial membrane.The Fo portion forms a proton channel that allows the flow of protons back into the mitochondrial matrix. As protons flow through the Fo channel, it causes a rotation of the F1 portion. This rotation drives a series of conformational changes in the F1 portion, which facilitates the synthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi).
The large internal space of Mitochondria filled with gel like substance called matrix which is closed by inner membrane of Mitochondria. matrix plays a vital role in several metabolic processes, including the citric acid cycle (also known as the Krebs cycle) and the oxidation of fatty acids. It also contains single circular ds (mtDNA), RNAs, 70S ribosomes and enzymes for TCA cycle.
The outer membrane is a relatively smooth and porous structure that surrounds the mitochondrion. It is composed of a phospholipid bilayer. It contains several proteins, including porins, which facilitate the transport of metabolites and small proteins into the intermembrane space. It acts as a barrier, protecting the contents of the mitochondrion from the cytoplasmic environment. It helps maintain the integrity of the organelle and prevents the leakage of mitochondrial components.
The outer membrane is a relatively smooth and porous structure that surrounds the mitochondrion. It is composed of a phospholipid bilayer. It contains several proteins, including porins, which facilitate the transport of metabolites and small proteins into the intermembrane space. It acts as a barrier, protecting the contents of the mitochondrion from the cytoplasmic environment. It helps maintain the integrity of the organelle and prevents the leakage of mitochondrial components.
Mitochondria as semi autonomous organelle
Mitochondria are also called semi autonomous organelle as they have their own genetic material for duplication and able to synthesize some of their own proteins with the help of 70s ribosomes, however most of the mitochondrial proteins are encoded by nuclear genetic material (dsDNA).
This symbiotic relationship becomes more permanent over the time,that bacterium lost some of its independent functions and transferred much of its genetic material to the host cell's nucleus. This process is known as endosymbiotic gene transfer.The host cell also developed mechanisms to regulate and control the symbiont, ensuring that it continued to provide energy.
Endosymbiotic theory- origin of mitochondria
According to this theory an ancestral Eukaryotic cell which lack mitochondria, engulf a free living bacterium. This bacterium was aerobic in nature. This eukaryotic cell instead of digesting that bacterium established a mutual relationship between them. The bacterium provided energy to the host cell by performing aerobic respiration, a process that generates adenosine triphosphate (ATP) through the breakdown of organic molecules. In return, the host cell provided protection and a stable environment for the bacterium.This symbiotic relationship becomes more permanent over the time,that bacterium lost some of its independent functions and transferred much of its genetic material to the host cell's nucleus. This process is known as endosymbiotic gene transfer.The host cell also developed mechanisms to regulate and control the symbiont, ensuring that it continued to provide energy.
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2) mitochondria has proteins called porins in the outer membrane which resembles with that of bacteria.
3) mitochondria have their own DNA and RNA and 70s ribosome as that of bacteria.
4) Protein synthesis in mitochondria is inhibited by variety of antibiotics that also resembles the same inhibition of protein synthesis by bacterial ribosome.
5) size of Mitochondria is approximately same as that of bacteria.
2) It is double membrane bound organelle in which outer membrane is acts as protective layer and contains several proteins called porins.
3) inner membrane has several infoldings called cristae in which oxysomes are embedded and these oxysomes synthes ATP.
4) It is also called semi autonomous organelle because it has its own DNA ,ribosomes and RNA.
5) The endosymbiotic theory gives the evidences that mitochondria was earlier a aerobic bacterium engulfed by a lacking eukayotic cell.
6) Matrix of mitochondria is a gel like substance plays a vital role in citric acid cycle (also known as the Krebs cycle) and the oxidation of fatty acids. It also contains single circular ds (mtDNA), RNAs, 70S ribosomes and enzymes for TCA cycle.
Ans- The main function of mitochondria is to generate energy in the form of adenosine triphosphate (ATP) through a process called cellular respiration.
Ques-2 who discovered mitochondria?
Ans- The discovery of mitochondria is credited to two scientists: Richard Altmann and Carl Benda.
In 1886, Richard Altmann, a German pathologist, first observed small granules within cells and named them "bioblasts." He later renamed them "mitochondria".
Around the same time, in 1898, Carl Benda, a German physician, independently described similar structures within cells and referred to them as "elementary organisms" because he believed they were separate entities within the cell.
Ques-3 what is another name for mitochondria?
Ans- Another name for mitochondria is "the powerhouse of the cell." This nickname is widely used because mitochondria are primarily responsible for generating energy in the form of ATP through cellular respiration. The term "powerhouse" emphasizes the central role of mitochondria in supplying the energy necessary for various cellular activities.
Ques-4 what is the origin of Mitochondria?
Ans- According to this theory an ancestral Eukaryotic cell which lack mitochondria, engulf a free living bacterium. This bacterium was aerobic in nature. This eukaryotic cell instead of digesting that bacterium established a mutual relationship between them. The bacterium provided energy to the host cell by performing aerobic respiration, a process that generates adenosine triphosphate (ATP) through the breakdown of organic molecules. In return, the host cell provided protection and a stable environment for the bacterium.
Ques-5 what is cristea in biology?
Ans- In biology, a "crista" refers to the folded inner membrane of a mitochondrion. These cristae increase the surface area of the inner membrane, allowing for more efficient production of ATP (adenosine triphosphate) during cellular respiration.
Evidences of Endosymbiotic theory
1) Mitochondria is a self replicating organly like bacteria and divide by binary fission as bacteria do.2) mitochondria has proteins called porins in the outer membrane which resembles with that of bacteria.
3) mitochondria have their own DNA and RNA and 70s ribosome as that of bacteria.
4) Protein synthesis in mitochondria is inhibited by variety of antibiotics that also resembles the same inhibition of protein synthesis by bacterial ribosome.
5) size of Mitochondria is approximately same as that of bacteria.
Conclusion:-
1) mitochondria is called the power house of the cell because it is a site of aerobic respiration.2) It is double membrane bound organelle in which outer membrane is acts as protective layer and contains several proteins called porins.
3) inner membrane has several infoldings called cristae in which oxysomes are embedded and these oxysomes synthes ATP.
4) It is also called semi autonomous organelle because it has its own DNA ,ribosomes and RNA.
5) The endosymbiotic theory gives the evidences that mitochondria was earlier a aerobic bacterium engulfed by a lacking eukayotic cell.
6) Matrix of mitochondria is a gel like substance plays a vital role in citric acid cycle (also known as the Krebs cycle) and the oxidation of fatty acids. It also contains single circular ds (mtDNA), RNAs, 70S ribosomes and enzymes for TCA cycle.
FAQs:-
Ques-1 what is the main function of Mitochondria?Ans- The main function of mitochondria is to generate energy in the form of adenosine triphosphate (ATP) through a process called cellular respiration.
Ques-2 who discovered mitochondria?
Ans- The discovery of mitochondria is credited to two scientists: Richard Altmann and Carl Benda.
In 1886, Richard Altmann, a German pathologist, first observed small granules within cells and named them "bioblasts." He later renamed them "mitochondria".
Around the same time, in 1898, Carl Benda, a German physician, independently described similar structures within cells and referred to them as "elementary organisms" because he believed they were separate entities within the cell.
Ques-3 what is another name for mitochondria?
Ans- Another name for mitochondria is "the powerhouse of the cell." This nickname is widely used because mitochondria are primarily responsible for generating energy in the form of ATP through cellular respiration. The term "powerhouse" emphasizes the central role of mitochondria in supplying the energy necessary for various cellular activities.
Ques-4 what is the origin of Mitochondria?
Ans- According to this theory an ancestral Eukaryotic cell which lack mitochondria, engulf a free living bacterium. This bacterium was aerobic in nature. This eukaryotic cell instead of digesting that bacterium established a mutual relationship between them. The bacterium provided energy to the host cell by performing aerobic respiration, a process that generates adenosine triphosphate (ATP) through the breakdown of organic molecules. In return, the host cell provided protection and a stable environment for the bacterium.
Ques-5 what is cristea in biology?
Ans- In biology, a "crista" refers to the folded inner membrane of a mitochondrion. These cristae increase the surface area of the inner membrane, allowing for more efficient production of ATP (adenosine triphosphate) during cellular respiration.
Nice content, very helpful.
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