The Mitochondri The Role Of Energy In The Human Body
The human body is a very complex working system and it requires a lot of energy to function properly. The human body eats food molecules that contain nutrients in order to get the energy needed to function. Once these food molecules are broken down in the human body some of the nutrients are made into glucose, which is an energy source. This glucose is not quite usable as one whole thing so our body breaks down even more into other molecules like pyruvate. Eventually the human body needs to make these pyruvates into usable energy. The human body does through the mitochondria.
The mitochondria is an organelle used to create energy for the human body. It was described first by Richard Altmann in 1890 ("Mitochondria."). Altman described the mitochondria as a rod shaped organelle found in most cells ("Mitochondria."). The mitochondria is a very complex organelle made up of many different parts. It is a double membrane organelle that consists of an inner and an outer membrane ("Structure of Mitochondria." ). There is space between these two membranes and this space is called the inner membrane space ("Structure of Mitochondria." ). On the other side of the inner membrane there is a space called the mitochondrial matrix ("Structure of Mitochondria." ). The inner membrane also has a lot of folds that extend into the membrane called cristae ("Structure of …show more content…
Mitochondria.").
All of these parts of the mitochondria have very specific duties when making energy for the body. The membranes of the mitochondria is a phospholipid bilayer which allows necessary molecules in the
mitochondria like ADP, ATP, ions, and more.("Structure of Mitochondria."). The inner membrane contains proteins that make up the electron transport chain, an enzyme called ATP synthase which makes ATP and transports proteins ("Structure of Mitochondria."). The inner membrane is also very picky about what enters and leaves the membrane ("Structure of Mitochondria."). The mitochondrial matrix stores very important information such as the mitochondrial genome, otherwise know as the mitochondrial DNA, ribosomes, tRNAs and much more ("What Is the Function of the Matrix in the Mitochondria?"). The mitochondria is vital for the cell’s functions. Its main job is to create usable energy called adenosine triphosphate or ATP ("Function of Mitochondria."). The mitochondria makes ATP from food molecules brought into the body (Alberts, Bray, Hopkins, Johnson, Lewis, Raff, Roberts, & Walter, 428-429). ATP is created when the mitochondria changes pyruvate into acetyl CoA which powers the citric acid cycle (Alberts et al., 428-429).The citric acid cycle starts when acetyl CoA and oxaloacetate are catalyzed by citrate synthase making S citryl CoA intermediate (Alberts et al., 428-429). Once this is made water is added making Citrate with HS CoA and a hydrogen atom is left. Step two of the cycle is where citrate is catalyzed by aconitase making cis aconitate intermediate and extracting a water molecule (Alberts et al., 428-429). Once this cis aconitate intermediate is made water is added back making isocitrate (Alberts et al., 428-429). Step three involves isocitrate being catalyzed by isocitrate dehydrogenase and a NAD plus carrier making Oxalosuccinate intermediate and one NADH and leaving out a hydrogen atom (Alberts et al., 428-429). Once this oxalosuccinate intermediate is made the hydrogen atom is added making CO2 and a-ketoglutarate (Alberts et al., 428-429). The fourth step is where a-ketoglutarate plus HS-CoA is catalyzed by a ketoglutarate dehydrogenase complex and one NAD plus carrier makes one NADH, succinyl CoA, one hydrogen atom, and one CO2 molecule (Alberts et al., 428-429). Next, in the fifth step, succinyl CoA is catalyzed by H20, a phosphate group, GDP, and succinyl Coa Synthetase making one GTP molecule and succinate (Alberts et al., 428-429). Step six involves succinate being catalyzed by one FAD carrier and succinate dehydrogenase making one FADH2 carrier and fumarate (Alberts et al., 428-429). In step seven fumarate is catalyzed by fumarase and is given a water molecule making malate (Alberts et al., 428-429). The final step of the citric acid cycle is where malate is catalyzed by one NAD plus carrier and malate dehydrogenase, making one NADH carrier and oxaloacetate and leaving one hydrogen atom out (Alberts et al., 428-429). Once this oxaloacetate is made, it is again catalyzed with acetyl CoA and the next citric acid cycle begins (Alberts et al., 428-429).
The mitochondria makes ATP for the cell in other ways as well. Another way the mitochondria makes energy for the cell is through the electron transport chain (“The Electron Transport Chain Steps Simplified.”). The electron transport chain makes thirty-four ATP molecules, compared to the citric acid cycle which makes two ATP (“The Electron Transport Chain Steps Simplified.”). The way the electron transport chain works is high energy electron carriers go through different complexes on the inner mitochondrial membrane making ATP (“The Electron Transport Chain: Products and Steps.” ).
Production of ATP synthesis is not the only role of the mitochondria. Another role of the mitochondria is non shivering thermogenesis ("Function of Mitochondria."). Thermogenesis is the production of heat, specifically dealing with the physiologic process of heat production in the body(G). Non shivering thermogenesis is caused by the diffusion of protons into the mitochondrial matrix or otherwise know as proton leak or mitochondrial uncoupling ("Function of Mitochondria."). Non shivering thermogenesis occurs very rarely, but when it does occur the proton leak causes unharnessed potential energy of the protons electrochemical gradient to be expelled as heat the highest form of energy ("Function of Mitochondria."). Non shivering thermogenesis happens mostly in brown adipose tissue or brown fat because the process is operated by a protein that is found in brown fat ("Function of Mitochondria."). This protein called thermogenin or UCP1 behaves like a proton channel and sometimes allows protons to enter the mitochondrial matrix while not contributing to ATP synthesis ("Function of Mitochondria."). Non shivering thermogenesis rarely occurs in adult human mitochondrial because humans have small amounts of brown fat molecules in them. It does occur in young human bodies because they have a lot of brown fat present at birth but the brown fat is lost as age increases ("Function of Mitochondria."). Mostly non shivering thermogenesis happens in animals that hibernate like a brown bear. Because of how cold the environment is the brown bear needs a lot of heat to survive ("Function of Mitochondria."). In one case, after World War II, mice were found alive in a food freezer at the temperature of -10 degrees celsius (Cannon & Nedergaard, 15). Scientists wondered how these mice could survive and prosper without shivering all their life (Cannon & Nedergaard, 15). Eventually it was discovered that the mice's bodies constantly underwent nonshivering thermogenesis causing their metabolism to elevate thus allowing the mice to survive and prosper in the extremely cold conditions (Cannon & Nedergaard, 15).
The mitochondria serves yet another role in the body. It also plays a role in cell apoptosis ("Programmed Cell Death (Apoptosis)."). Apoptosis is a genetically regulated process that leads to the programmed death of cells which is triggered by the the presence or lack of specific stimuli ("Programmed Cell Death (Apoptosis)."). The mitochondria's role in cell apoptosis is to safeguard cell survival and also facilitate apoptosis when the time comes ("Function of Mitochondria."). What happens to the mitochondria when apoptosis is needed? Proapoptotic proteins enter the mitochondrial membrane, causing pores to form in the membrane. ("Function of Mitochondria.") Next, the protein cytochrome, moves from the intermembrane space of the mitochondria through the pores, made by the proapoptotic proteins, of the mitochondrial membrane ("Function of Mitochondria."). Then, the protein cytochrome leaves the mitochondrial membrane entering the cytosol ("Function of Mitochondria."). Finally, once cytochrome is in the cytosol it stimulates many biochemical changes causing apoptotic death of a cell ("Function of Mitochondria.").
Yet another major role the mitochondria plays is in the storage of CA two plus molecules, also know as calcium molecules ("Function of Mitochondria."). Calcium is necessary for survival ("Calcium/Vitamin D."). Calcium has many functions including building bones and keeping the bones healthy, helping out with blood clots, and allowing muscles to contract ("Calcium/Vitamin D."). Calcium also assists with fertilization ("Calcium/Vitamin D."). Humans store most of their calcium in bone tissues ("Function of Mitochondria."). At a cellular level calcium his held in two organelles ("Function of Mitochondria."). Those organelles are the endoplasmic reticulum and the mitochondrial ("Function of Mitochondria."). While the endoplasmic reticulum is the main site where calcium is stored, the mitochondria does store some calcium ("Function of Mitochondria."). The storage of calcium in the mitochondria helps contribute to a cell's homeostasis of calcium which is important in keeping balance within the cell ("Function of Mitochondria."). The mitochondria does this by acting as a cytosolic buffer for calcium ("Function of Mitochondria.").
Mitochondria has its own DNA. The mitochondrial DNA is independent of the DNA of the organism ("Function of Mitochondria."). The mitochondria’s DNA inherited from their maternally side ("Function of Mitochondria."). This means that the genes are inherited through extranuclear elements that are found in the cytoplasm of the egg ("Function of Mitochondria." ). Mitochondrial DNA makes up about one percent of a cells total cellular DNA ("Function of Mitochondria."). Like DNA mitochondrial DNA has its own genome and it can make mistakes copying its genome, leading to mutations ("Function of Mitochondria."). These mutations can cause diseases such as Alpers Disease which leads to seizures, dementia, spasticity, blindness, liver dysfunction, and cerebral degeneration ("Types of Mitochondrial Disease."). Luf Disease which causes hypermetabolism is also believed to be a mutation in mitochondrial DNA. Luf Disease is characterized by fever, heat intolerance, profuse perspiration, polyphagia, polydipsia, ragged-red fibers, and resting tachycardia (("Types of Mitochondrial Disease.")). Recent studies are leaning towards mitochondrial mutations being a trigger for alzheimer's disease ("Mitochondrial Dysfunction is a Trigger of Alzheimer's Disease Pathophysiology."). It is not clear yet, but scientists are trying to determine if mitochondrial dysfunction can lead to alzheimer's, due of the lack of energy or wrongly activating cell apoptosis ("Mitochondrial Dysfunction is a Trigger of Alzheimer's Disease Pathophysiology."). Mitochondria is a vital organelle in every cell. It has many key functions that help organisms survive. It produces energy in the usable form of ATP and it uses the citric acid cycle to make two ATP molecules. Mitochondria also uses the electron transport chain to make thirty-four ATP. The mitochondria helps activate cellular apoptosis, while it also limits cellular apoptosis. It also is a storage site for calcium which is very important nutrient for organisms. The mitochondria is responsible for non shivering thermogenesis which allows the body to make heat without shivering. Finally the mitochondria has its own special DNA which always it to carry out its many functions, but this DNA can also become mutated and leads to diseases. The mitochondria is essentially the powerhouse of an organism and it allows the organism to produce energy in order to survive.
The mitochondria is an organelle used to create energy for the human body. It was described first by Richard Altmann in 1890 ("Mitochondria."). Altman described the mitochondria as a rod shaped organelle found in most cells ("Mitochondria."). The mitochondria is a very complex organelle made up of many different parts. It is a double membrane organelle that consists of an inner and an outer membrane ("Structure of Mitochondria." ). There is space between these two membranes and this space is called the inner membrane space ("Structure of Mitochondria." ). On the other side of the inner membrane there is a space called the mitochondrial matrix ("Structure of Mitochondria." ). The inner membrane also has a lot of folds that extend into the membrane called cristae ("Structure of …show more content…
Mitochondria.").
All of these parts of the mitochondria have very specific duties when making energy for the body. The membranes of the mitochondria is a phospholipid bilayer which allows necessary molecules in the
mitochondria like ADP, ATP, ions, and more.("Structure of Mitochondria."). The inner membrane contains proteins that make up the electron transport chain, an enzyme called ATP synthase which makes ATP and transports proteins ("Structure of Mitochondria."). The inner membrane is also very picky about what enters and leaves the membrane ("Structure of Mitochondria."). The mitochondrial matrix stores very important information such as the mitochondrial genome, otherwise know as the mitochondrial DNA, ribosomes, tRNAs and much more ("What Is the Function of the Matrix in the Mitochondria?"). The mitochondria is vital for the cell’s functions. Its main job is to create usable energy called adenosine triphosphate or ATP ("Function of Mitochondria."). The mitochondria makes ATP from food molecules brought into the body (Alberts, Bray, Hopkins, Johnson, Lewis, Raff, Roberts, & Walter, 428-429). ATP is created when the mitochondria changes pyruvate into acetyl CoA which powers the citric acid cycle (Alberts et al., 428-429).The citric acid cycle starts when acetyl CoA and oxaloacetate are catalyzed by citrate synthase making S citryl CoA intermediate (Alberts et al., 428-429). Once this is made water is added making Citrate with HS CoA and a hydrogen atom is left. Step two of the cycle is where citrate is catalyzed by aconitase making cis aconitate intermediate and extracting a water molecule (Alberts et al., 428-429). Once this cis aconitate intermediate is made water is added back making isocitrate (Alberts et al., 428-429). Step three involves isocitrate being catalyzed by isocitrate dehydrogenase and a NAD plus carrier making Oxalosuccinate intermediate and one NADH and leaving out a hydrogen atom (Alberts et al., 428-429). Once this oxalosuccinate intermediate is made the hydrogen atom is added making CO2 and a-ketoglutarate (Alberts et al., 428-429). The fourth step is where a-ketoglutarate plus HS-CoA is catalyzed by a ketoglutarate dehydrogenase complex and one NAD plus carrier makes one NADH, succinyl CoA, one hydrogen atom, and one CO2 molecule (Alberts et al., 428-429). Next, in the fifth step, succinyl CoA is catalyzed by H20, a phosphate group, GDP, and succinyl Coa Synthetase making one GTP molecule and succinate (Alberts et al., 428-429). Step six involves succinate being catalyzed by one FAD carrier and succinate dehydrogenase making one FADH2 carrier and fumarate (Alberts et al., 428-429). In step seven fumarate is catalyzed by fumarase and is given a water molecule making malate (Alberts et al., 428-429). The final step of the citric acid cycle is where malate is catalyzed by one NAD plus carrier and malate dehydrogenase, making one NADH carrier and oxaloacetate and leaving one hydrogen atom out (Alberts et al., 428-429). Once this oxaloacetate is made, it is again catalyzed with acetyl CoA and the next citric acid cycle begins (Alberts et al., 428-429).
The mitochondria makes ATP for the cell in other ways as well. Another way the mitochondria makes energy for the cell is through the electron transport chain (“The Electron Transport Chain Steps Simplified.”). The electron transport chain makes thirty-four ATP molecules, compared to the citric acid cycle which makes two ATP (“The Electron Transport Chain Steps Simplified.”). The way the electron transport chain works is high energy electron carriers go through different complexes on the inner mitochondrial membrane making ATP (“The Electron Transport Chain: Products and Steps.” ).
Production of ATP synthesis is not the only role of the mitochondria. Another role of the mitochondria is non shivering thermogenesis ("Function of Mitochondria."). Thermogenesis is the production of heat, specifically dealing with the physiologic process of heat production in the body(G). Non shivering thermogenesis is caused by the diffusion of protons into the mitochondrial matrix or otherwise know as proton leak or mitochondrial uncoupling ("Function of Mitochondria."). Non shivering thermogenesis occurs very rarely, but when it does occur the proton leak causes unharnessed potential energy of the protons electrochemical gradient to be expelled as heat the highest form of energy ("Function of Mitochondria."). Non shivering thermogenesis happens mostly in brown adipose tissue or brown fat because the process is operated by a protein that is found in brown fat ("Function of Mitochondria."). This protein called thermogenin or UCP1 behaves like a proton channel and sometimes allows protons to enter the mitochondrial matrix while not contributing to ATP synthesis ("Function of Mitochondria."). Non shivering thermogenesis rarely occurs in adult human mitochondrial because humans have small amounts of brown fat molecules in them. It does occur in young human bodies because they have a lot of brown fat present at birth but the brown fat is lost as age increases ("Function of Mitochondria."). Mostly non shivering thermogenesis happens in animals that hibernate like a brown bear. Because of how cold the environment is the brown bear needs a lot of heat to survive ("Function of Mitochondria."). In one case, after World War II, mice were found alive in a food freezer at the temperature of -10 degrees celsius (Cannon & Nedergaard, 15). Scientists wondered how these mice could survive and prosper without shivering all their life (Cannon & Nedergaard, 15). Eventually it was discovered that the mice's bodies constantly underwent nonshivering thermogenesis causing their metabolism to elevate thus allowing the mice to survive and prosper in the extremely cold conditions (Cannon & Nedergaard, 15).
The mitochondria serves yet another role in the body. It also plays a role in cell apoptosis ("Programmed Cell Death (Apoptosis)."). Apoptosis is a genetically regulated process that leads to the programmed death of cells which is triggered by the the presence or lack of specific stimuli ("Programmed Cell Death (Apoptosis)."). The mitochondria's role in cell apoptosis is to safeguard cell survival and also facilitate apoptosis when the time comes ("Function of Mitochondria."). What happens to the mitochondria when apoptosis is needed? Proapoptotic proteins enter the mitochondrial membrane, causing pores to form in the membrane. ("Function of Mitochondria.") Next, the protein cytochrome, moves from the intermembrane space of the mitochondria through the pores, made by the proapoptotic proteins, of the mitochondrial membrane ("Function of Mitochondria."). Then, the protein cytochrome leaves the mitochondrial membrane entering the cytosol ("Function of Mitochondria."). Finally, once cytochrome is in the cytosol it stimulates many biochemical changes causing apoptotic death of a cell ("Function of Mitochondria.").
Yet another major role the mitochondria plays is in the storage of CA two plus molecules, also know as calcium molecules ("Function of Mitochondria."). Calcium is necessary for survival ("Calcium/Vitamin D."). Calcium has many functions including building bones and keeping the bones healthy, helping out with blood clots, and allowing muscles to contract ("Calcium/Vitamin D."). Calcium also assists with fertilization ("Calcium/Vitamin D."). Humans store most of their calcium in bone tissues ("Function of Mitochondria."). At a cellular level calcium his held in two organelles ("Function of Mitochondria."). Those organelles are the endoplasmic reticulum and the mitochondrial ("Function of Mitochondria."). While the endoplasmic reticulum is the main site where calcium is stored, the mitochondria does store some calcium ("Function of Mitochondria."). The storage of calcium in the mitochondria helps contribute to a cell's homeostasis of calcium which is important in keeping balance within the cell ("Function of Mitochondria."). The mitochondria does this by acting as a cytosolic buffer for calcium ("Function of Mitochondria.").
Mitochondria has its own DNA. The mitochondrial DNA is independent of the DNA of the organism ("Function of Mitochondria."). The mitochondria’s DNA inherited from their maternally side ("Function of Mitochondria."). This means that the genes are inherited through extranuclear elements that are found in the cytoplasm of the egg ("Function of Mitochondria." ). Mitochondrial DNA makes up about one percent of a cells total cellular DNA ("Function of Mitochondria."). Like DNA mitochondrial DNA has its own genome and it can make mistakes copying its genome, leading to mutations ("Function of Mitochondria."). These mutations can cause diseases such as Alpers Disease which leads to seizures, dementia, spasticity, blindness, liver dysfunction, and cerebral degeneration ("Types of Mitochondrial Disease."). Luf Disease which causes hypermetabolism is also believed to be a mutation in mitochondrial DNA. Luf Disease is characterized by fever, heat intolerance, profuse perspiration, polyphagia, polydipsia, ragged-red fibers, and resting tachycardia (("Types of Mitochondrial Disease.")). Recent studies are leaning towards mitochondrial mutations being a trigger for alzheimer's disease ("Mitochondrial Dysfunction is a Trigger of Alzheimer's Disease Pathophysiology."). It is not clear yet, but scientists are trying to determine if mitochondrial dysfunction can lead to alzheimer's, due of the lack of energy or wrongly activating cell apoptosis ("Mitochondrial Dysfunction is a Trigger of Alzheimer's Disease Pathophysiology."). Mitochondria is a vital organelle in every cell. It has many key functions that help organisms survive. It produces energy in the usable form of ATP and it uses the citric acid cycle to make two ATP molecules. Mitochondria also uses the electron transport chain to make thirty-four ATP. The mitochondria helps activate cellular apoptosis, while it also limits cellular apoptosis. It also is a storage site for calcium which is very important nutrient for organisms. The mitochondria is responsible for non shivering thermogenesis which allows the body to make heat without shivering. Finally the mitochondria has its own special DNA which always it to carry out its many functions, but this DNA can also become mutated and leads to diseases. The mitochondria is essentially the powerhouse of an organism and it allows the organism to produce energy in order to survive.