Electron Transport Chain and Oxidative Phosphorylation - MCAT Biology
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The drug, DNP, destroys the H+ gradient that forms in the electron transport chain. What is the most likely consequence?
The drug, DNP, destroys the H+ gradient that forms in the electron transport chain. What is the most likely consequence?
If the proton gradient of the electron transport chain were to be destroyed, the cell would need to perform cellular respiration without an electron transport chain. The only option would be to move to anaerobic respiration, which requires fermentation.
If the proton gradient of the electron transport chain were to be destroyed, the cell would need to perform cellular respiration without an electron transport chain. The only option would be to move to anaerobic respiration, which requires fermentation.
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Given a healthy individual with a normal metabolic rate, which of the following compounds is the most energy rich?
Given a healthy individual with a normal metabolic rate, which of the following compounds is the most energy rich?
This question is asking about ATP production during cellular respiration. During oxidative phosphorylation (the electron transport chain), each 1 ATP is produced for each GTP, 2 ATP are produced for each FADH2, and 3 ATP are produced for each NADH.
This question is asking about ATP production during cellular respiration. During oxidative phosphorylation (the electron transport chain), each 1 ATP is produced for each GTP, 2 ATP are produced for each FADH2, and 3 ATP are produced for each NADH.
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A person is born with a mutation that causes their cells to not have the ability to produce the NADH dehydrogenase complex, the complex that allows the electron transport chain to make ATP from NADH. Will this patient be able to produce any enery at all from the ETC?
A person is born with a mutation that causes their cells to not have the ability to produce the NADH dehydrogenase complex, the complex that allows the electron transport chain to make ATP from NADH. Will this patient be able to produce any enery at all from the ETC?
FADH2 enters the ETC at the succinate-Q oxidoreductase complex. While this doesn't generate as much energy as NADH will because the electrons travel a shorter distance, there are still 2 ATP molecules made for each FADH2.
FADH2 enters the ETC at the succinate-Q oxidoreductase complex. While this doesn't generate as much energy as NADH will because the electrons travel a shorter distance, there are still 2 ATP molecules made for each FADH2.
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Scientists use a process called Flourescent In-Situ Hybridization, or FISH, to study genetic disorders in humans. FISH is a technique that uses spectrographic analysis to determine the presence or absence, as well as the relative abundance, of genetic material in human cells.
To use FISH, scientists apply fluorescently-labeled bits of DNA of a known color, called probes, to samples of test DNA. These probes anneal to the sample DNA, and scientists can read the colors that result using laboratory equipment. One common use of FISH is to determine the presence of extra DNA in conditions of aneuploidy, a state in which a human cell has an abnormal number of chromosomes. Chromosomes are collections of DNA, the totality of which makes up a cell’s genome. Another typical use is in the study of cancer cells, where scientists use FISH labels to ascertain if genes have moved inappropriately in a cell’s genome.
Using red fluorescent tags, scientists label probe DNA for a gene known to be expressed more heavily in cancer cells than normal cells. They then label a probe for an immediately adjacent DNA sequence with a green fluorescent tag. Both probes are then added to three dishes, shown below. In dish 1 human bladder cells are incubated with the probes, in dish 2 human epithelial cells are incubated, and in dish 3 known non-cancerous cells are used. The relative luminescence observed in regions of interest in all dishes is shown below.
Cancer cells require large amounts of energy in the form of ATP. Which of the following processes results in the greatest production of ATP?
Scientists use a process called Flourescent In-Situ Hybridization, or FISH, to study genetic disorders in humans. FISH is a technique that uses spectrographic analysis to determine the presence or absence, as well as the relative abundance, of genetic material in human cells.
To use FISH, scientists apply fluorescently-labeled bits of DNA of a known color, called probes, to samples of test DNA. These probes anneal to the sample DNA, and scientists can read the colors that result using laboratory equipment. One common use of FISH is to determine the presence of extra DNA in conditions of aneuploidy, a state in which a human cell has an abnormal number of chromosomes. Chromosomes are collections of DNA, the totality of which makes up a cell’s genome. Another typical use is in the study of cancer cells, where scientists use FISH labels to ascertain if genes have moved inappropriately in a cell’s genome.
Using red fluorescent tags, scientists label probe DNA for a gene known to be expressed more heavily in cancer cells than normal cells. They then label a probe for an immediately adjacent DNA sequence with a green fluorescent tag. Both probes are then added to three dishes, shown below. In dish 1 human bladder cells are incubated with the probes, in dish 2 human epithelial cells are incubated, and in dish 3 known non-cancerous cells are used. The relative luminescence observed in regions of interest in all dishes is shown below.
Cancer cells require large amounts of energy in the form of ATP. Which of the following processes results in the greatest production of ATP?
Oxidative phosphorylation in the mitochondria is the major contributor to the total ATP pool in most eukaryotic cells. Keep in mind that it is oxidative phosphorylation in concert with the proton gradient that drives the electron transport chain.
Oxidative phosphorylation in the mitochondria is the major contributor to the total ATP pool in most eukaryotic cells. Keep in mind that it is oxidative phosphorylation in concert with the proton gradient that drives the electron transport chain.
Compare your answer with the correct one above
Scientists use a process called Flourescent In-Situ Hybridization, or FISH, to study genetic disorders in humans. FISH is a technique that uses spectrographic analysis to determine the presence or absence, as well as the relative abundance, of genetic material in human cells.
To use FISH, scientists apply fluorescently-labeled bits of DNA of a known color, called probes, to samples of test DNA. These probes anneal to the sample DNA, and scientists can read the colors that result using laboratory equipment. One common use of FISH is to determine the presence of extra DNA in conditions of aneuploidy, a state in which a human cell has an abnormal number of chromosomes. Chromosomes are collections of DNA, the totality of which makes up a cell’s genome. Another typical use is in the study of cancer cells, where scientists use FISH labels to ascertain if genes have moved inappropriately in a cell’s genome.
Using red fluorescent tags, scientists label probe DNA for a gene known to be expressed more heavily in cancer cells than normal cells. They then label a probe for an immediately adjacent DNA sequence with a green fluorescent tag. Both probes are then added to three dishes, shown below. In dish 1 human bladder cells are incubated with the probes, in dish 2 human epithelial cells are incubated, and in dish 3 known non-cancerous cells are used. The relative luminescence observed in regions of interest in all dishes is shown below.
A new treatment for bladder cancer is developed that targets energy production in malignant cells. Which of the following potential target sites would directly involve the synthesis of most of the ATP in a cell?
Scientists use a process called Flourescent In-Situ Hybridization, or FISH, to study genetic disorders in humans. FISH is a technique that uses spectrographic analysis to determine the presence or absence, as well as the relative abundance, of genetic material in human cells.
To use FISH, scientists apply fluorescently-labeled bits of DNA of a known color, called probes, to samples of test DNA. These probes anneal to the sample DNA, and scientists can read the colors that result using laboratory equipment. One common use of FISH is to determine the presence of extra DNA in conditions of aneuploidy, a state in which a human cell has an abnormal number of chromosomes. Chromosomes are collections of DNA, the totality of which makes up a cell’s genome. Another typical use is in the study of cancer cells, where scientists use FISH labels to ascertain if genes have moved inappropriately in a cell’s genome.
Using red fluorescent tags, scientists label probe DNA for a gene known to be expressed more heavily in cancer cells than normal cells. They then label a probe for an immediately adjacent DNA sequence with a green fluorescent tag. Both probes are then added to three dishes, shown below. In dish 1 human bladder cells are incubated with the probes, in dish 2 human epithelial cells are incubated, and in dish 3 known non-cancerous cells are used. The relative luminescence observed in regions of interest in all dishes is shown below.
A new treatment for bladder cancer is developed that targets energy production in malignant cells. Which of the following potential target sites would directly involve the synthesis of most of the ATP in a cell?
ATP synthase is housed on the inner mitochondrial membrane, and is the main ATP production agent in oxidative phosphorylation. It provides a channel for protons to enter the matrix from the intermembrane space, and in so doing, drives ATP production.
ATP synthase is housed on the inner mitochondrial membrane, and is the main ATP production agent in oxidative phosphorylation. It provides a channel for protons to enter the matrix from the intermembrane space, and in so doing, drives ATP production.
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What phase of cellular respiration has the highest ATP yield?
What phase of cellular respiration has the highest ATP yield?
Oxidative phosphorylation, which traps energy in a high-energy phosphate bond and uses an electron gradient and ATP synthase to create ATP, yields the most ATP. Oxidative phosphorylation is linked with the electron transport chain.
Glycolysis only gives a net of two ATP per glucose, and the Krebs cycle gives two GTP for every turn of the cycle. Gluconeogenesis is not a part of cellular respiration, and fermentation is very low-yield since it occurs in the absence of oxygen.
Oxidative phosphorylation, which traps energy in a high-energy phosphate bond and uses an electron gradient and ATP synthase to create ATP, yields the most ATP. Oxidative phosphorylation is linked with the electron transport chain.
Glycolysis only gives a net of two ATP per glucose, and the Krebs cycle gives two GTP for every turn of the cycle. Gluconeogenesis is not a part of cellular respiration, and fermentation is very low-yield since it occurs in the absence of oxygen.
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Why is oxygen necessary in aerobic cellular respiration?
Why is oxygen necessary in aerobic cellular respiration?
Oxygen is the final electron acceptor in the electron transport chain, which results in the production of water. Glycolysis does not require oxygen, and can be done in anaerobic environments. NADH is the molecule which is oxidized in order to establish the proton gradient. Finally, oxygen is not needed to create oxaloacetic acid is the Kreb's cycle, as it is regenerated after each turn of the cycle.
Oxygen is the final electron acceptor in the electron transport chain, which results in the production of water. Glycolysis does not require oxygen, and can be done in anaerobic environments. NADH is the molecule which is oxidized in order to establish the proton gradient. Finally, oxygen is not needed to create oxaloacetic acid is the Kreb's cycle, as it is regenerated after each turn of the cycle.
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Imagine that a toxin is introduced to the body and inhibits the establishment of the proton gradient in the intermembrane space. What would you predict would be the result?
Imagine that a toxin is introduced to the body and inhibits the establishment of the proton gradient in the intermembrane space. What would you predict would be the result?
ATP synthase is dependent on a proton gradient in the intermembrane space in order to produce ATP. As a result, the toxin will make it inactive. Oxidative phosphorylation would be inhibited in this case, as opposed to substrate-level phosphorylation.
Pyruvate is a product of glycolysis, and would not be affected by the toxin. NADH is key in the establishment of the proton gradient, so we would expect that it would be unable to be oxidized due to the toxin. Protons produced in the conversion of NADH to NAD+ (+H+) establish the proton gradient. If the gradient is absent, NADH is likely not be oxidized.
ATP synthase is dependent on a proton gradient in the intermembrane space in order to produce ATP. As a result, the toxin will make it inactive. Oxidative phosphorylation would be inhibited in this case, as opposed to substrate-level phosphorylation.
Pyruvate is a product of glycolysis, and would not be affected by the toxin. NADH is key in the establishment of the proton gradient, so we would expect that it would be unable to be oxidized due to the toxin. Protons produced in the conversion of NADH to NAD+ (+H+) establish the proton gradient. If the gradient is absent, NADH is likely not be oxidized.
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Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
One of the main arguments in favor of the theory of endosymbiosis is that mitochondria have their own genome. Which of the following cellular structures is most likely to be coded for only by mitochondrial DNA?
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
One of the main arguments in favor of the theory of endosymbiosis is that mitochondria have their own genome. Which of the following cellular structures is most likely to be coded for only by mitochondrial DNA?
Electron transport chain (ETC) proteins are encoded by the the mitochondrial DNA. This makes sense, as we find ETC proteins only in the mitochondrial membrane (remember, as the passage states, aerobic metabolism is limited to the mitochondria).
It may be tempting to select glycolytic enzymes, as the free living predecessors to mitochondria presumably underwent glycolysis; however, these genes have been lost as the symbiosis matured and glycolysis was localized to the cellular cytosol.
Electron transport chain (ETC) proteins are encoded by the the mitochondrial DNA. This makes sense, as we find ETC proteins only in the mitochondrial membrane (remember, as the passage states, aerobic metabolism is limited to the mitochondria).
It may be tempting to select glycolytic enzymes, as the free living predecessors to mitochondria presumably underwent glycolysis; however, these genes have been lost as the symbiosis matured and glycolysis was localized to the cellular cytosol.
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Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
With regard to the energy production by the mitochondria discussed in the passage, what is the main factor driving ATP production at the terminal step of aerobic metabolism?
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
With regard to the energy production by the mitochondria discussed in the passage, what is the main factor driving ATP production at the terminal step of aerobic metabolism?
The final step in aerobic metabolism is the capture of the stored energy of protons existing in the intermembrane space. The electrochemical gradient in the intermembrane space forces protons through ATP synthase, phosphorylating ADP.
Glucose is converted to pyruvate during glycolysis, and to lactate during anaerobic respiration.
The final step in aerobic metabolism is the capture of the stored energy of protons existing in the intermembrane space. The electrochemical gradient in the intermembrane space forces protons through ATP synthase, phosphorylating ADP.
Glucose is converted to pyruvate during glycolysis, and to lactate during anaerobic respiration.
Compare your answer with the correct one above
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
The primary purpose of the electron transport chain of mitochondria described in the passage is __________.
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
The primary purpose of the electron transport chain of mitochondria described in the passage is __________.
The electron transport chain serves to pump protons into the intermembrane space. The result is the buildup of the electrochemical gradient, and the passage of protons through ATP synthase. Essentially, the electron transport chain establishes the conditions for oxidative phosphorylation to occur.
The electron transport chain serves to pump protons into the intermembrane space. The result is the buildup of the electrochemical gradient, and the passage of protons through ATP synthase. Essentially, the electron transport chain establishes the conditions for oxidative phosphorylation to occur.
Compare your answer with the correct one above
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
A scientist is studying typical mitochondria as described in the passage. In the course of his study, he measures the generation of NADH and FADH2. What is the normal destination of NADH and FADH2?
Most scientists subscribe to the theory of endosymbiosis to explain the presence of mitochondria in eukaryotic cells. According to the theory of endosymbiosis, early pre-eukaryotic cells phagocytosed free living prokaryotes, but failed to digest them. As a result, these prokaryotes remained in residence in the pre-eukaryotes, and continued to generate energy. The host cells were able to use this energy to gain a selective advantage over their competitors, and eventually the energy-producing prokaryotes became mitochondria.
In many ways, mitochondria are different from other cellular organelles, and these differences puzzled scientists for many years. The theory of endosymbiosis concisely explains a number of these observations about mitochondria. Perhaps most of all, the theory explains why aerobic metabolism is entirely limited to this one organelle, while other kinds of metabolism are more distributed in the cellular cytosol.
A scientist is studying typical mitochondria as described in the passage. In the course of his study, he measures the generation of NADH and FADH2. What is the normal destination of NADH and FADH2?
NADH and FADH2 are electron carriers. They bring electrons from their production point (glycolysis or the Kreb's cycle) to the electron transport chain proteins. The electrons are then passed down the electron transport chain to generate energy.
NADH and FADH2 are electron carriers. They bring electrons from their production point (glycolysis or the Kreb's cycle) to the electron transport chain proteins. The electrons are then passed down the electron transport chain to generate energy.
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Which of these processes in aerobic respiration would not be possible in the absence of oxygen?
Which of these processes in aerobic respiration would not be possible in the absence of oxygen?
Oxygen is necessary to be the last electron acceptor in the electron transport chain. This results in the formation of water.
Oxygen is not involved in glycolysis, which utilizes substrate-level phosphorylation, nor is it needed for the Krebs cycle. NAD+ is converted to NADH during glycolysis and the Krebs cycle without involving oxygen.
Oxygen is necessary to be the last electron acceptor in the electron transport chain. This results in the formation of water.
Oxygen is not involved in glycolysis, which utilizes substrate-level phosphorylation, nor is it needed for the Krebs cycle. NAD+ is converted to NADH during glycolysis and the Krebs cycle without involving oxygen.
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Which of the following areas of the mitochondria has the lowest pH?
Which of the following areas of the mitochondria has the lowest pH?
ATP synthase, which is located on the inner mitochondrial membrane, requires a proton gradient in order to create ATP. This means that the protons need to be pumped across the inner mitochondrial membrane into the intermembrane space. This results in the intermembrane space having the lowest pH in the mitochondria, due to the high proton concentration.
The mitochondrial matrix is the interior of the inner mitochondrial membrane, while the cytosol is not a part of the mitochondria. Neither of these have particularly low pH values. Christae are the folds of the inner mitochondrial membrane that increase its surface area for the electron transport chain processes; though structurally useful in facilitating respiration, the pH of christae is roughly the same as that of the mitochondrial matrix.
ATP synthase, which is located on the inner mitochondrial membrane, requires a proton gradient in order to create ATP. This means that the protons need to be pumped across the inner mitochondrial membrane into the intermembrane space. This results in the intermembrane space having the lowest pH in the mitochondria, due to the high proton concentration.
The mitochondrial matrix is the interior of the inner mitochondrial membrane, while the cytosol is not a part of the mitochondria. Neither of these have particularly low pH values. Christae are the folds of the inner mitochondrial membrane that increase its surface area for the electron transport chain processes; though structurally useful in facilitating respiration, the pH of christae is roughly the same as that of the mitochondrial matrix.
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During aerobic respiration, which of the following pathways correctly orders the process of cellular metabolism after glycolysis in eukaryotic cells?
During aerobic respiration, which of the following pathways correctly orders the process of cellular metabolism after glycolysis in eukaryotic cells?
After glycolysis is complete, we have generated pyruvate from glucose. We would then expect pyruvate decarboxylation to be the first step after glycolysis in aerobic respiration. When pyruvate is decarboxylated, we generate acetyl CoA, which fuels the Krebs cycle (aka TCA, and citric acid cycle). We would expect the next step after decarboxylation to be the citric acid cycle. In the citric acid cycle we generate FADH2 and NADH, which release free energy in oxidative phosphorylation to generate the proton gradient across the mitochondrial membrane to fuel ATP synthase.
After glycolysis is complete, we have generated pyruvate from glucose. We would then expect pyruvate decarboxylation to be the first step after glycolysis in aerobic respiration. When pyruvate is decarboxylated, we generate acetyl CoA, which fuels the Krebs cycle (aka TCA, and citric acid cycle). We would expect the next step after decarboxylation to be the citric acid cycle. In the citric acid cycle we generate FADH2 and NADH, which release free energy in oxidative phosphorylation to generate the proton gradient across the mitochondrial membrane to fuel ATP synthase.
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Which of these are examples of passive transport?
I. Simple diffusion
II. Voltage-gated channels
III. Channel proteins
IV. Proton pump
Which of these are examples of passive transport?
I. Simple diffusion
II. Voltage-gated channels
III. Channel proteins
IV. Proton pump
The two main classifications for transport are active transport and passive transport. Active transport requires the conversion of ATP to ADP, and generally involves pumping molecules against their concentration gradients. Passive transport, in contrast, does not require the use of cellular energy.
Any form of diffusion, either simple diffusion through a membrane or facilitated diffusion via a channel protein, qualifies as passive transport and does not require ATP mediation. Similarly, voltage-gated channels require a certain electrical environment to mediate their function, but do not require the presence of ATP. Proton pumps act to push protons against their concentration gradient, and require the input of cellular energy, thus qualifying as active transport.
The two main classifications for transport are active transport and passive transport. Active transport requires the conversion of ATP to ADP, and generally involves pumping molecules against their concentration gradients. Passive transport, in contrast, does not require the use of cellular energy.
Any form of diffusion, either simple diffusion through a membrane or facilitated diffusion via a channel protein, qualifies as passive transport and does not require ATP mediation. Similarly, voltage-gated channels require a certain electrical environment to mediate their function, but do not require the presence of ATP. Proton pumps act to push protons against their concentration gradient, and require the input of cellular energy, thus qualifying as active transport.
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A deficiency in which of the following within the mitochondrial matrix will not limit a cell's rate of oxidative phosphorylation?
A deficiency in which of the following within the mitochondrial matrix will not limit a cell's rate of oxidative phosphorylation?
Oxidative phosphorylation is dependent on the functionality of the electron transport chain. In the electron transport chain, NADH and FADH2 act as electron donors. The donated electrons are used by protein complexes along the inner mitochondrial membrane to establish the proton gradient in the intermembrane space. Once the electrons have passed through the complexes, they are donated to an oxygen molecule to create water. Oxygen is the final electron acceptor in the chain, and is essential for oxidative phosphorylation to occur.
NAD+ is the precursor of NADH, making it another crucial molecule for cell metabolism. NAD+ is converted to NADH during glycolysis and the Krebs cycle. A deficiency of NAD+ in the mitochondrial matrix will slow the Krebs cycle, which will turn slow oxidative phosphorylation.
Oxidative phosphorylation is dependent on the functionality of the electron transport chain. In the electron transport chain, NADH and FADH2 act as electron donors. The donated electrons are used by protein complexes along the inner mitochondrial membrane to establish the proton gradient in the intermembrane space. Once the electrons have passed through the complexes, they are donated to an oxygen molecule to create water. Oxygen is the final electron acceptor in the chain, and is essential for oxidative phosphorylation to occur.
NAD+ is the precursor of NADH, making it another crucial molecule for cell metabolism. NAD+ is converted to NADH during glycolysis and the Krebs cycle. A deficiency of NAD+ in the mitochondrial matrix will slow the Krebs cycle, which will turn slow oxidative phosphorylation.
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When a certain bacterium undergoes aerobic respiration, which area would have the lowest pH?
When a certain bacterium undergoes aerobic respiration, which area would have the lowest pH?
Bacteria are prokaryotes. Since prokaryotes do not have any membrane bound organelles, during respiration, protons are pumped from the cytoplasm to the extracellular region between the plasma membrane and the cell wall. This results in a gradient between those two regions, thus extracellular would have a lower pH.
Bacteria are prokaryotes. Since prokaryotes do not have any membrane bound organelles, during respiration, protons are pumped from the cytoplasm to the extracellular region between the plasma membrane and the cell wall. This results in a gradient between those two regions, thus extracellular would have a lower pH.
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Cyanide is very toxic in high enough doses because it binds irreversibly to cytochrome C. Which of the following is not an effect of cyanide's inhibition of cytochrome C?
Cyanide is very toxic in high enough doses because it binds irreversibly to cytochrome C. Which of the following is not an effect of cyanide's inhibition of cytochrome C?
The inhibition of cytochrome C means that the electron transport chain is no longer able to shuttle electrons from complex III to complex IV, which means it is no longer able to accept electrons from electron carriers. As a result, the citric acid cycle would slow down since there would be a build-up of NADH, which allosterically inhibits several enzymes in the citric acid cycle.
Since the electron transport chain no longer functions properly, there wouldn't be as many 
ions being pumped into the intermembrane space, which would increase the pH in the intermembrane space. Also, with the decline in the 
concentration, oxidative phosphorylation would no longer be efficient, and the cell would have to increase rate of fermentation to increase energy output.
The inhibition of cytochrome C means that the electron transport chain is no longer able to shuttle electrons from complex III to complex IV, which means it is no longer able to accept electrons from electron carriers. As a result, the citric acid cycle would slow down since there would be a build-up of NADH, which allosterically inhibits several enzymes in the citric acid cycle.
Since the electron transport chain no longer functions properly, there wouldn't be as many
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The drug, DNP, destroys the H+ gradient that forms in the electron transport chain. What is the most likely consequence?
The drug, DNP, destroys the H+ gradient that forms in the electron transport chain. What is the most likely consequence?
If the proton gradient of the electron transport chain were to be destroyed, the cell would need to perform cellular respiration without an electron transport chain. The only option would be to move to anaerobic respiration, which requires fermentation.
If the proton gradient of the electron transport chain were to be destroyed, the cell would need to perform cellular respiration without an electron transport chain. The only option would be to move to anaerobic respiration, which requires fermentation.
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