Other Concepts - MCAT Biological and Biochemical Foundations of Living Systems
Card 1 of 96
A vitamin is defined as an organic molecule that is required to be obtained from the diet because it cannot be synthesized by the organism. Based on this definition, which of the following is not a true vitamin?
A vitamin is defined as an organic molecule that is required to be obtained from the diet because it cannot be synthesized by the organism. Based on this definition, which of the following is not a true vitamin?
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Although there are recommended intake values for vitamin D, this "vitamin" can be synthesized by the body with the help of UV radiation from the sun.
Although there are recommended intake values for vitamin D, this "vitamin" can be synthesized by the body with the help of UV radiation from the sun.
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A man must have his duodenum completely removed. During the surgery, the stomach will be connected to the jejunum. As a result of the surgery, the patient will likely suffer from which of the following conditions?
A man must have his duodenum completely removed. During the surgery, the stomach will be connected to the jejunum. As a result of the surgery, the patient will likely suffer from which of the following conditions?
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The duodenum and jejunum are two adjacent regions of the small intestine. The duodenum is the region in which the majority of chemical digestion occurs. The pancreas secretes several critical digestive enzymes into the duodenum. One of these enzymes is lipase, which is responsible for lipid digestion. Removal of this region would result in an inability to digest lipids.
Production of vitamin K mostly occurs in the large intestine, digestion of polysaccharides to disaccharides is accomplished with salivary amylase, water absorption occurs in the large intestine, and bile is produced by the liver.
The duodenum and jejunum are two adjacent regions of the small intestine. The duodenum is the region in which the majority of chemical digestion occurs. The pancreas secretes several critical digestive enzymes into the duodenum. One of these enzymes is lipase, which is responsible for lipid digestion. Removal of this region would result in an inability to digest lipids.
Production of vitamin K mostly occurs in the large intestine, digestion of polysaccharides to disaccharides is accomplished with salivary amylase, water absorption occurs in the large intestine, and bile is produced by the liver.
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The cell is the most basic functional unit of life. Everything that we consider to be living is made up of cells, and while there are different kinds of cells, they all have some essential features that link them all together under the category of "life." One of the most important parts of a cell is the membrane that surrounds it, seperating it from the rest of the environment.
While organisms from the three main domains live in incredibly different environments, they all possess similar cell membranes. This phospholipid bilayer protects the cell, giving it a way to allow certain things in while keeping other things out. Though organisms from different domains have different kinds of fatty linkages in their membranes, they all serve this essential purpose.
Membranes contain all kinds of essential proteins and signal molecules that allow the inside of the cell to respond to the outside of the cell. In a multicellular eukaryote, this ability can be used to allow cells to communicate. In a bacterial colony, an extracellular signal could be used to signal other bacteria. Signals cascade through a series of molecular pathways that go from the outside of the cell all the way to the nucleus and back out again, giving the cell control on a genetic level. This allows cellular responses to be quick and effective, and it also allows the cell to control how long it stays in that state.
Fire was once debated over to decide if it should be considered alive or not; however, fire is not made of cells, so it was decided that it was indeed not alive. Which answer choice is NOT a tenet of all living things?
The cell is the most basic functional unit of life. Everything that we consider to be living is made up of cells, and while there are different kinds of cells, they all have some essential features that link them all together under the category of "life." One of the most important parts of a cell is the membrane that surrounds it, seperating it from the rest of the environment.
While organisms from the three main domains live in incredibly different environments, they all possess similar cell membranes. This phospholipid bilayer protects the cell, giving it a way to allow certain things in while keeping other things out. Though organisms from different domains have different kinds of fatty linkages in their membranes, they all serve this essential purpose.
Membranes contain all kinds of essential proteins and signal molecules that allow the inside of the cell to respond to the outside of the cell. In a multicellular eukaryote, this ability can be used to allow cells to communicate. In a bacterial colony, an extracellular signal could be used to signal other bacteria. Signals cascade through a series of molecular pathways that go from the outside of the cell all the way to the nucleus and back out again, giving the cell control on a genetic level. This allows cellular responses to be quick and effective, and it also allows the cell to control how long it stays in that state.
Fire was once debated over to decide if it should be considered alive or not; however, fire is not made of cells, so it was decided that it was indeed not alive. Which answer choice is NOT a tenet of all living things?
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The four incorrect answers are simply the foundation of the Cell Theory, and you should know them. While all cells have a membrane enclosing the whole cell, not all have a membrane-bound nucleus. Prokaryotes have a nucloid that contains most of the genetic material, but it is not bound.
The four incorrect answers are simply the foundation of the Cell Theory, and you should know them. While all cells have a membrane enclosing the whole cell, not all have a membrane-bound nucleus. Prokaryotes have a nucloid that contains most of the genetic material, but it is not bound.
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Thermoregulation of the human body is controlled by a .
Thermoregulation of the human body is controlled by a .
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Like many biological functions, thermoregulation is controlled by a negative feedback system. This is because the response is the opposite of the input: a hot environment triggers cooling, while a cool environment triggers heating. A positive feedback system would intensify a response in the same direction as the input. If a positive feedback mechanisms were true of regulating body temperature, cold weather would trigger sweating and dilation of blood vessels. The result would be that you would get even more cold, which would not be good for maintaining homeostasis. Hormones do help regulate many body functions, but they are not the best description of how body temperature is controlled.
Like many biological functions, thermoregulation is controlled by a negative feedback system. This is because the response is the opposite of the input: a hot environment triggers cooling, while a cool environment triggers heating. A positive feedback system would intensify a response in the same direction as the input. If a positive feedback mechanisms were true of regulating body temperature, cold weather would trigger sweating and dilation of blood vessels. The result would be that you would get even more cold, which would not be good for maintaining homeostasis. Hormones do help regulate many body functions, but they are not the best description of how body temperature is controlled.
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The cell theory describes the properties that are the basis of life. Which of the following is not a tenet of the cell theory?
The cell theory describes the properties that are the basis of life. Which of the following is not a tenet of the cell theory?
Tap to reveal answer
Not all cells need to undergo oxidative phosphorylation to produce energy; they can also use anaerobic respiration or other methods of energy production.
The cell theory states that all living things are made of one of more cells, and that a cell is the basic functional unit of life. The theory claims that any cell must have originated from a pre-existing cell, detailing the concept of cellular reproduction. These three claims form the broad arc od concepts of the cell theory. Additional sub-claims to the theory dictate that cells contain DNA and require energy (nutrients).
Not all cells need to undergo oxidative phosphorylation to produce energy; they can also use anaerobic respiration or other methods of energy production.
The cell theory states that all living things are made of one of more cells, and that a cell is the basic functional unit of life. The theory claims that any cell must have originated from a pre-existing cell, detailing the concept of cellular reproduction. These three claims form the broad arc od concepts of the cell theory. Additional sub-claims to the theory dictate that cells contain DNA and require energy (nutrients).
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Which of the following accurately describes the body of a fresh water fish immediately following its transfer to a salt-water aquarium?
Which of the following accurately describes the body of a fresh water fish immediately following its transfer to a salt-water aquarium?
Tap to reveal answer
In its home environment, the fresh water fish will be in equilibrium with its surroundings. As such, it will essentially be isotonic with a fresh water solution. This represents a relatively low solute concentration in the fish's body.
When we transfer this fish to a medium that is more densely concentrated with solute molecules, the fresh-water fish will be hypotonic in relation to the external medium. The salt in the surrounding water will cause the external environment to be more concentrated than the body of the fish. As a result, the fish will quickly become dehydrated as water exits its body.
Hypertonic and hyperosmotic are synonyms, which both refer to greater concentrations than the surroundings (opposite the scenario described).
In its home environment, the fresh water fish will be in equilibrium with its surroundings. As such, it will essentially be isotonic with a fresh water solution. This represents a relatively low solute concentration in the fish's body.
When we transfer this fish to a medium that is more densely concentrated with solute molecules, the fresh-water fish will be hypotonic in relation to the external medium. The salt in the surrounding water will cause the external environment to be more concentrated than the body of the fish. As a result, the fish will quickly become dehydrated as water exits its body.
Hypertonic and hyperosmotic are synonyms, which both refer to greater concentrations than the surroundings (opposite the scenario described).
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A container has a semi-permeable membrane separating equal volumes of equimolar aqueous glucose and sodium hydroxide solutions. Which of the following describes the heights of the solutions after the system has equilibrated?
A container has a semi-permeable membrane separating equal volumes of equimolar aqueous glucose and sodium hydroxide solutions. Which of the following describes the heights of the solutions after the system has equilibrated?
Tap to reveal answer
Answering this question depends on your knowledge of concentration gradients and solution chemistry. Even though the sodium hydroxide and glucose solutions are equimolar, sodium hydroxide is an electrolyte, meaning it dissociates when in solution. The solute content of the sodium hydroxide solution is actually twice that of the glucose solution due to the presence of ions. This means that the sodium hydroxide solution will actually be hypertonic with respect to the glucose solution.
Only water can cross the semi-permeable membrane; the ions will be trapped in their respective chambers. Water from the glucose solution will diffuse down its concentration gradient into the sodium hydroxide solution. After the system equilibrates, the water level in the sodium hydroxide solution will be higher.
Answering this question depends on your knowledge of concentration gradients and solution chemistry. Even though the sodium hydroxide and glucose solutions are equimolar, sodium hydroxide is an electrolyte, meaning it dissociates when in solution. The solute content of the sodium hydroxide solution is actually twice that of the glucose solution due to the presence of ions. This means that the sodium hydroxide solution will actually be hypertonic with respect to the glucose solution.
Only water can cross the semi-permeable membrane; the ions will be trapped in their respective chambers. Water from the glucose solution will diffuse down its concentration gradient into the sodium hydroxide solution. After the system equilibrates, the water level in the sodium hydroxide solution will be higher.
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Certain inhibitors bind enzymes irreversibly through covalent bonding. Would the kinetics (V vs. \[S\] curve) of this be similar to that of a reversible noncompetitive inhibitor? Why?
Certain inhibitors bind enzymes irreversibly through covalent bonding. Would the kinetics (V vs. \[S\] curve) of this be similar to that of a reversible noncompetitive inhibitor? Why?
Tap to reveal answer
An irreversible noncompetitive inhibitor permanently deactivates some enzyme function. Therefore, the effective enzyme concentration will be reduced, which is also what is observed through using a reversible noncompetitive inhibitor. 
is unaffected by noncompetitive inhibitors.
An irreversible noncompetitive inhibitor permanently deactivates some enzyme function. Therefore, the effective enzyme concentration will be reduced, which is also what is observed through using a reversible noncompetitive inhibitor.
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Which of the following types of enzymes irreversibly modifies its substrate?
Which of the following types of enzymes irreversibly modifies its substrate?
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Proteases are enzymes that cleave substrates at certain locations. This permanently removes a part of the protein and thus is irreversible. Kinases catalyze the phosphorylation of proteins. Since phosphatases do the opposite, we know that phosphate groups can be reversibly added to proteins. Ligases catalyze the joining of two molecules together, which is reversible since large dimers and polymers are broken down all the time.
Proteases are enzymes that cleave substrates at certain locations. This permanently removes a part of the protein and thus is irreversible. Kinases catalyze the phosphorylation of proteins. Since phosphatases do the opposite, we know that phosphate groups can be reversibly added to proteins. Ligases catalyze the joining of two molecules together, which is reversible since large dimers and polymers are broken down all the time.
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Which fo the following marks a distinct quality of smooth muscle?
Which fo the following marks a distinct quality of smooth muscle?
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Smooth muscle varies from other muscle types because it has the capacity to develop tension slowly, but maintain contractions for a longer period. The autorhythmic cells within smooth muscle generate slow wave or pacemaker potentials that allow tension to develop slowly. Think, for example, of the smooth muscle that surrounds the bladder and generates tension slowly or of the smooth muscle that controls the size of the pupil and must maintain contractions for extended periods.
Smooth muscle varies from other muscle types because it has the capacity to develop tension slowly, but maintain contractions for a longer period. The autorhythmic cells within smooth muscle generate slow wave or pacemaker potentials that allow tension to develop slowly. Think, for example, of the smooth muscle that surrounds the bladder and generates tension slowly or of the smooth muscle that controls the size of the pupil and must maintain contractions for extended periods.
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The parietal cells of the stomach are vital for both food digestion and as a defense mechanism against pathogens. When the parietal cells are not functioning properly, diseases such sepsis due to Clostridium difficile and malnutrition may occur. To keep the digestive system healthy, proper nutrition as well as a balanced diet is vital.
The parietal cells of the stomach secrete hydrochloric acid via the hormone gastrin. Gastrin is released when the stomach distends, via the presence of proteins and/or indirectly by the vagus nerve from the parasympathetic nervous system. Hydrochloric acid breaks down certain ingested food as well as activates certain zymogens for further digestion of macromolecules. The high acidity of the stomach due to the release of hydrochloric acid by parietal cells also destroys most pathogens. When the parietal cell is not functioning properly, opportunistic pathogens may create health problems.
Parietal cells also secrete intrinsic factor, a glycoprotein which binds to vitamin B12 to prevent destruction of the vitamin by the hydrochloric acid. Down the gastrointestinal tract, the vitamin is absorbed by the ileum of the small intestine. Vitamin B12 is essential for red blood cell production. A diet low in vitamin B12 may lead to anemia.
When the acidity of the stomach is too high, somatostatin is secreted by the D cells of the stomach. somatostatin inhibits the parietal cells from releasing more hydrochloric acid. What type of feedback is this?
The parietal cells of the stomach are vital for both food digestion and as a defense mechanism against pathogens. When the parietal cells are not functioning properly, diseases such sepsis due to Clostridium difficile and malnutrition may occur. To keep the digestive system healthy, proper nutrition as well as a balanced diet is vital.
The parietal cells of the stomach secrete hydrochloric acid via the hormone gastrin. Gastrin is released when the stomach distends, via the presence of proteins and/or indirectly by the vagus nerve from the parasympathetic nervous system. Hydrochloric acid breaks down certain ingested food as well as activates certain zymogens for further digestion of macromolecules. The high acidity of the stomach due to the release of hydrochloric acid by parietal cells also destroys most pathogens. When the parietal cell is not functioning properly, opportunistic pathogens may create health problems.
Parietal cells also secrete intrinsic factor, a glycoprotein which binds to vitamin B12 to prevent destruction of the vitamin by the hydrochloric acid. Down the gastrointestinal tract, the vitamin is absorbed by the ileum of the small intestine. Vitamin B12 is essential for red blood cell production. A diet low in vitamin B12 may lead to anemia.
When the acidity of the stomach is too high, somatostatin is secreted by the D cells of the stomach. somatostatin inhibits the parietal cells from releasing more hydrochloric acid. What type of feedback is this?
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The increase in acidity of the stomach will activate the D Cells in the stomach to secrete somatostatin. somatostatin will then inhibit the parietal cells from releasing hydrochloric acid. This is a form of negative feedback since a downstream
The increase in acidity of the stomach will activate the D Cells in the stomach to secrete somatostatin. somatostatin will then inhibit the parietal cells from releasing hydrochloric acid. This is a form of negative feedback since a downstream
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The cellular membrane is a very important structure. The lipid bilayer is both hydrophilic and hydrophobic. The hydrophilic layer faces the extracellular fluid and the cytosol of the cell. The hydrophobic portion of the lipid bilayer stays in between the hydrophobic regions like a sandwich. This bilayer separation allows for communication, protection, and homeostasis.
One of the most utilized signaling transduction pathways is the G protein-coupled receptor pathway. The hydrophobic and hydrophilic properties of the cellular membrane allows for the peptide and other hydrophilic hormones to bind to the receptor on the cellular surface but to not enter the cell. This regulation allows for activation despite the hormone’s short half-life. On the other hand, hydrophobic hormones must have longer half-lives to allow for these ligands to cross the lipid bilayer, travel through the cell’s cytosol and eventually reach the nucleus.
Cholesterol allows the lipid bilayer to maintain its fluidity despite the fluctuation in the body’s temperature due to events such as increasing metabolism. Cholesterol binds to the hydrophobic tails of the lipid bilayer. When the temperature is low, the cholesterol molecules prevent the hydrophobic tails from compacting and solidifying. When the temperature is high, the hydrophobic tails will be excited and will move excessively. This excess movement will bring instability to the bilayer. Cholesterol will prevent excessive movement.
Epinephrine binds to its receptor on the surface of the cell. Molecule B also binds to the same receptor but when bound, all of the receptors on the cell's surface are upregulated. What type of regulation is this?
The cellular membrane is a very important structure. The lipid bilayer is both hydrophilic and hydrophobic. The hydrophilic layer faces the extracellular fluid and the cytosol of the cell. The hydrophobic portion of the lipid bilayer stays in between the hydrophobic regions like a sandwich. This bilayer separation allows for communication, protection, and homeostasis.
One of the most utilized signaling transduction pathways is the G protein-coupled receptor pathway. The hydrophobic and hydrophilic properties of the cellular membrane allows for the peptide and other hydrophilic hormones to bind to the receptor on the cellular surface but to not enter the cell. This regulation allows for activation despite the hormone’s short half-life. On the other hand, hydrophobic hormones must have longer half-lives to allow for these ligands to cross the lipid bilayer, travel through the cell’s cytosol and eventually reach the nucleus.
Cholesterol allows the lipid bilayer to maintain its fluidity despite the fluctuation in the body’s temperature due to events such as increasing metabolism. Cholesterol binds to the hydrophobic tails of the lipid bilayer. When the temperature is low, the cholesterol molecules prevent the hydrophobic tails from compacting and solidifying. When the temperature is high, the hydrophobic tails will be excited and will move excessively. This excess movement will bring instability to the bilayer. Cholesterol will prevent excessive movement.
Epinephrine binds to its receptor on the surface of the cell. Molecule B also binds to the same receptor but when bound, all of the receptors on the cell's surface are upregulated. What type of regulation is this?
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This is an example of cooperation because the activation of one will positively regulate others.
This is an example of cooperation because the activation of one will positively regulate others.
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The cell is the most basic functional unit of life. Everything that we consider to be living is made up of cells, and while there are different kinds of cells, they all have some essential features that link them all together under the category of "life." One of the most important parts of a cell is the membrane that surrounds it, seperating it from the rest of the environment.
While organisms from the three main domains live in incredibly different environments, they all possess similar cell membranes. This phospholipid bilayer protects the cell, giving it a way to allow certain things in while keeping other things out. Though organisms from different domains have different kinds of fatty linkages in their membranes, they all serve this essential purpose.
Membranes contain all kinds of essential proteins and signal molecules that allow the inside of the cell to respond to the outside of the cell. In a multicellular eukaryote, this ability can be used to allow cells to communicate. In a bacterial colony, an extracellular signal could be used to signal other bacteria. Signals cascade through a series of molecular pathways that go from the outside of the cell all the way to the nucleus and back out again, giving the cell control on a genetic level. This allows cellular responses to be quick and effective, and it also allows the cell to control how long it stays in that state.
Fire was once debated over to decide if it should be considered alive or not; however, fire is not made of cells, so it was decided that it was indeed not alive. Which answer choice is NOT a tenet of all living things?
The cell is the most basic functional unit of life. Everything that we consider to be living is made up of cells, and while there are different kinds of cells, they all have some essential features that link them all together under the category of "life." One of the most important parts of a cell is the membrane that surrounds it, seperating it from the rest of the environment.
While organisms from the three main domains live in incredibly different environments, they all possess similar cell membranes. This phospholipid bilayer protects the cell, giving it a way to allow certain things in while keeping other things out. Though organisms from different domains have different kinds of fatty linkages in their membranes, they all serve this essential purpose.
Membranes contain all kinds of essential proteins and signal molecules that allow the inside of the cell to respond to the outside of the cell. In a multicellular eukaryote, this ability can be used to allow cells to communicate. In a bacterial colony, an extracellular signal could be used to signal other bacteria. Signals cascade through a series of molecular pathways that go from the outside of the cell all the way to the nucleus and back out again, giving the cell control on a genetic level. This allows cellular responses to be quick and effective, and it also allows the cell to control how long it stays in that state.
Fire was once debated over to decide if it should be considered alive or not; however, fire is not made of cells, so it was decided that it was indeed not alive. Which answer choice is NOT a tenet of all living things?
Tap to reveal answer
The four incorrect answers are simply the foundation of the Cell Theory, and you should know them. While all cells have a membrane enclosing the whole cell, not all have a membrane-bound nucleus. Prokaryotes have a nucloid that contains most of the genetic material, but it is not bound.
The four incorrect answers are simply the foundation of the Cell Theory, and you should know them. While all cells have a membrane enclosing the whole cell, not all have a membrane-bound nucleus. Prokaryotes have a nucloid that contains most of the genetic material, but it is not bound.
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Thermoregulation of the human body is controlled by a .
Thermoregulation of the human body is controlled by a .
Tap to reveal answer
Like many biological functions, thermoregulation is controlled by a negative feedback system. This is because the response is the opposite of the input: a hot environment triggers cooling, while a cool environment triggers heating. A positive feedback system would intensify a response in the same direction as the input. If a positive feedback mechanisms were true of regulating body temperature, cold weather would trigger sweating and dilation of blood vessels. The result would be that you would get even more cold, which would not be good for maintaining homeostasis. Hormones do help regulate many body functions, but they are not the best description of how body temperature is controlled.
Like many biological functions, thermoregulation is controlled by a negative feedback system. This is because the response is the opposite of the input: a hot environment triggers cooling, while a cool environment triggers heating. A positive feedback system would intensify a response in the same direction as the input. If a positive feedback mechanisms were true of regulating body temperature, cold weather would trigger sweating and dilation of blood vessels. The result would be that you would get even more cold, which would not be good for maintaining homeostasis. Hormones do help regulate many body functions, but they are not the best description of how body temperature is controlled.
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The cell theory describes the properties that are the basis of life. Which of the following is not a tenet of the cell theory?
The cell theory describes the properties that are the basis of life. Which of the following is not a tenet of the cell theory?
Tap to reveal answer
Not all cells need to undergo oxidative phosphorylation to produce energy; they can also use anaerobic respiration or other methods of energy production.
The cell theory states that all living things are made of one of more cells, and that a cell is the basic functional unit of life. The theory claims that any cell must have originated from a pre-existing cell, detailing the concept of cellular reproduction. These three claims form the broad arc od concepts of the cell theory. Additional sub-claims to the theory dictate that cells contain DNA and require energy (nutrients).
Not all cells need to undergo oxidative phosphorylation to produce energy; they can also use anaerobic respiration or other methods of energy production.
The cell theory states that all living things are made of one of more cells, and that a cell is the basic functional unit of life. The theory claims that any cell must have originated from a pre-existing cell, detailing the concept of cellular reproduction. These three claims form the broad arc od concepts of the cell theory. Additional sub-claims to the theory dictate that cells contain DNA and require energy (nutrients).
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Which of the following accurately describes the body of a fresh water fish immediately following its transfer to a salt-water aquarium?
Which of the following accurately describes the body of a fresh water fish immediately following its transfer to a salt-water aquarium?
Tap to reveal answer
In its home environment, the fresh water fish will be in equilibrium with its surroundings. As such, it will essentially be isotonic with a fresh water solution. This represents a relatively low solute concentration in the fish's body.
When we transfer this fish to a medium that is more densely concentrated with solute molecules, the fresh-water fish will be hypotonic in relation to the external medium. The salt in the surrounding water will cause the external environment to be more concentrated than the body of the fish. As a result, the fish will quickly become dehydrated as water exits its body.
Hypertonic and hyperosmotic are synonyms, which both refer to greater concentrations than the surroundings (opposite the scenario described).
In its home environment, the fresh water fish will be in equilibrium with its surroundings. As such, it will essentially be isotonic with a fresh water solution. This represents a relatively low solute concentration in the fish's body.
When we transfer this fish to a medium that is more densely concentrated with solute molecules, the fresh-water fish will be hypotonic in relation to the external medium. The salt in the surrounding water will cause the external environment to be more concentrated than the body of the fish. As a result, the fish will quickly become dehydrated as water exits its body.
Hypertonic and hyperosmotic are synonyms, which both refer to greater concentrations than the surroundings (opposite the scenario described).
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A container has a semi-permeable membrane separating equal volumes of equimolar aqueous glucose and sodium hydroxide solutions. Which of the following describes the heights of the solutions after the system has equilibrated?
A container has a semi-permeable membrane separating equal volumes of equimolar aqueous glucose and sodium hydroxide solutions. Which of the following describes the heights of the solutions after the system has equilibrated?
Tap to reveal answer
Answering this question depends on your knowledge of concentration gradients and solution chemistry. Even though the sodium hydroxide and glucose solutions are equimolar, sodium hydroxide is an electrolyte, meaning it dissociates when in solution. The solute content of the sodium hydroxide solution is actually twice that of the glucose solution due to the presence of ions. This means that the sodium hydroxide solution will actually be hypertonic with respect to the glucose solution.
Only water can cross the semi-permeable membrane; the ions will be trapped in their respective chambers. Water from the glucose solution will diffuse down its concentration gradient into the sodium hydroxide solution. After the system equilibrates, the water level in the sodium hydroxide solution will be higher.
Answering this question depends on your knowledge of concentration gradients and solution chemistry. Even though the sodium hydroxide and glucose solutions are equimolar, sodium hydroxide is an electrolyte, meaning it dissociates when in solution. The solute content of the sodium hydroxide solution is actually twice that of the glucose solution due to the presence of ions. This means that the sodium hydroxide solution will actually be hypertonic with respect to the glucose solution.
Only water can cross the semi-permeable membrane; the ions will be trapped in their respective chambers. Water from the glucose solution will diffuse down its concentration gradient into the sodium hydroxide solution. After the system equilibrates, the water level in the sodium hydroxide solution will be higher.
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A vitamin is defined as an organic molecule that is required to be obtained from the diet because it cannot be synthesized by the organism. Based on this definition, which of the following is not a true vitamin?
A vitamin is defined as an organic molecule that is required to be obtained from the diet because it cannot be synthesized by the organism. Based on this definition, which of the following is not a true vitamin?
Tap to reveal answer
Although there are recommended intake values for vitamin D, this "vitamin" can be synthesized by the body with the help of UV radiation from the sun.
Although there are recommended intake values for vitamin D, this "vitamin" can be synthesized by the body with the help of UV radiation from the sun.
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A man must have his duodenum completely removed. During the surgery, the stomach will be connected to the jejunum. As a result of the surgery, the patient will likely suffer from which of the following conditions?
A man must have his duodenum completely removed. During the surgery, the stomach will be connected to the jejunum. As a result of the surgery, the patient will likely suffer from which of the following conditions?
Tap to reveal answer
The duodenum and jejunum are two adjacent regions of the small intestine. The duodenum is the region in which the majority of chemical digestion occurs. The pancreas secretes several critical digestive enzymes into the duodenum. One of these enzymes is lipase, which is responsible for lipid digestion. Removal of this region would result in an inability to digest lipids.
Production of vitamin K mostly occurs in the large intestine, digestion of polysaccharides to disaccharides is accomplished with salivary amylase, water absorption occurs in the large intestine, and bile is produced by the liver.
The duodenum and jejunum are two adjacent regions of the small intestine. The duodenum is the region in which the majority of chemical digestion occurs. The pancreas secretes several critical digestive enzymes into the duodenum. One of these enzymes is lipase, which is responsible for lipid digestion. Removal of this region would result in an inability to digest lipids.
Production of vitamin K mostly occurs in the large intestine, digestion of polysaccharides to disaccharides is accomplished with salivary amylase, water absorption occurs in the large intestine, and bile is produced by the liver.
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Certain inhibitors bind enzymes irreversibly through covalent bonding. Would the kinetics (V vs. \[S\] curve) of this be similar to that of a reversible noncompetitive inhibitor? Why?
Certain inhibitors bind enzymes irreversibly through covalent bonding. Would the kinetics (V vs. \[S\] curve) of this be similar to that of a reversible noncompetitive inhibitor? Why?
Tap to reveal answer
An irreversible noncompetitive inhibitor permanently deactivates some enzyme function. Therefore, the effective enzyme concentration will be reduced, which is also what is observed through using a reversible noncompetitive inhibitor. is unaffected by noncompetitive inhibitors.
An irreversible noncompetitive inhibitor permanently deactivates some enzyme function. Therefore, the effective enzyme concentration will be reduced, which is also what is observed through using a reversible noncompetitive inhibitor.
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