Enzymes - AP Biology
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Which of the following does not affect enzyme activity?
Which of the following does not affect enzyme activity?
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pH and temperature affect enzyme activity, as there is an optimal pH and temperature for each enzyme, and a pH or temperature too far from the optimal level can cause the enzyme to denature. Substrate concentration affects enzyme activity; increasing substrate concentration will increase the rate of reaction to the point that the enzymes are saturated.
pH and temperature affect enzyme activity, as there is an optimal pH and temperature for each enzyme, and a pH or temperature too far from the optimal level can cause the enzyme to denature. Substrate concentration affects enzyme activity; increasing substrate concentration will increase the rate of reaction to the point that the enzymes are saturated.
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How do enzymes speed up a reaction?
How do enzymes speed up a reaction?
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Enzymes speed up reactions through lowering the activation energy, of the energy needed to break bonds of reactants. The activation energy is lowered through stabilizing the transition state; the active site of the enzyme better fits the substrate, allowing bonds to more readily be broken, requiring less energy.
Enzymes speed up reactions through lowering the activation energy, of the energy needed to break bonds of reactants. The activation energy is lowered through stabilizing the transition state; the active site of the enzyme better fits the substrate, allowing bonds to more readily be broken, requiring less energy.
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Which of the following macromolecules has a subcategory that acts to speed up biological reactions in the body?
Which of the following macromolecules has a subcategory that acts to speed up biological reactions in the body?
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Proteins commonly act to facilitate reactions that would otherwise not take place. By lowering activation energy, proteins often serve as catalysts. A protein catalyst in a biological reaction is known as an enzyme. All enzymes are proteins.
Proteins commonly act to facilitate reactions that would otherwise not take place. By lowering activation energy, proteins often serve as catalysts. A protein catalyst in a biological reaction is known as an enzyme. All enzymes are proteins.
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Which of the following is best defined as a chemical agent that changes the rate of a reaction without being consumed by that reaction?
Which of the following is best defined as a chemical agent that changes the rate of a reaction without being consumed by that reaction?
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A catalyst is a substance that can change the rate of a reaction without being consumed by the reaction. Catalysts only affect the speed of the reaction. If a reaction would not occur naturally then the addition of a catalyst will have no effect.
A catalyst is a substance that can change the rate of a reaction without being consumed by the reaction. Catalysts only affect the speed of the reaction. If a reaction would not occur naturally then the addition of a catalyst will have no effect.
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Which of the following would be an example of a catalyst?
Which of the following would be an example of a catalyst?
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Enzymes are proteins that act as catalysts for reactions. Enzymes are essential in enabling the proper function of human metabolism. If enzymes were absent then chemical traffic throughout the metabolic pathways would become backed up.
Enzymes are proteins that act as catalysts for reactions. Enzymes are essential in enabling the proper function of human metabolism. If enzymes were absent then chemical traffic throughout the metabolic pathways would become backed up.
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Enzymes are a type which of the following categories?
Enzymes are a type which of the following categories?
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Enzymes are catalytic proteins. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
Enzymes are catalytic proteins. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
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Enzymes are a type of which of the following organic molecules?
Enzymes are a type of which of the following organic molecules?
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Enzymes are proteins that act as catalysts for metabolism. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
Enzymes are proteins that act as catalysts for metabolism. Enzymes are essential in proper functioning of metabolism because without them chemical traffic throughout the metabolic pathways would become backed up.
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Which of the following terms can be defined as the initial investment of energy in a reaction that is required to break bonds in the reactant molecules?
Which of the following terms can be defined as the initial investment of energy in a reaction that is required to break bonds in the reactant molecules?
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The investment of energy required to start a reaction is called the free energy of activation or activation energy. Activation energy is usually in the form of heat from the surrounding area that molecules in the reaction absorb.
The investment of energy required to start a reaction is called the free energy of activation or activation energy. Activation energy is usually in the form of heat from the surrounding area that molecules in the reaction absorb.
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Which of the following factors has an effect on the rate at which enzymes catalyze a reaction?
Which of the following factors has an effect on the rate at which enzymes catalyze a reaction?
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The temperature and pH of the environment, as well as the concentration of the substrate and enzyme, all affect the rate at which an enzyme catalyzes a reaction. As a result, enzymes have optimal conditions in which they can work at peak efficiency.
The temperature and pH of the environment, as well as the concentration of the substrate and enzyme, all affect the rate at which an enzyme catalyzes a reaction. As a result, enzymes have optimal conditions in which they can work at peak efficiency.
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Which of the following factors affects enzyme activity?
Which of the following factors affects enzyme activity?
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Temperature and pH can affect enzyme activity because they may alter the shape and effectiveness of the enzyme through protein denaturation. Likewise, the availability of reactants and substrates controls the amount of product that the enzyme can catalyze during the reaction. If they are present in low concentrations, then they will inhibit the enzyme’s activity.
Temperature and pH can affect enzyme activity because they may alter the shape and effectiveness of the enzyme through protein denaturation. Likewise, the availability of reactants and substrates controls the amount of product that the enzyme can catalyze during the reaction. If they are present in low concentrations, then they will inhibit the enzyme’s activity.
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If an antibiotic binds the active site of an enzyme but does not change the structure of that enzyme, once removed, the enzyme returns to normal function. In this case, the antibiotic is acting via what enzyme interaction?
If an antibiotic binds the active site of an enzyme but does not change the structure of that enzyme, once removed, the enzyme returns to normal function. In this case, the antibiotic is acting via what enzyme interaction?
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Competitive inhibition occurs when an substrate or inhibitor compete with the normal substrate for binding the active sight of an enzyme. The proper functioning of the enzyme depends on the concentration ratio of inhibitor to enzyme or substrate to enzyme. The competitive inhibition of the enzyme in this case by the antibiotic has potentially bactericidal or bacteriostatic effect on the bacteria until that antibiotic concentration decreases. Negative feedback involves the product of a set of metabolic reactions inhibiting the formation of a precursor of that metabolic pathway, thereby decreasing its own production.
Competitive inhibition occurs when an substrate or inhibitor compete with the normal substrate for binding the active sight of an enzyme. The proper functioning of the enzyme depends on the concentration ratio of inhibitor to enzyme or substrate to enzyme. The competitive inhibition of the enzyme in this case by the antibiotic has potentially bactericidal or bacteriostatic effect on the bacteria until that antibiotic concentration decreases. Negative feedback involves the product of a set of metabolic reactions inhibiting the formation of a precursor of that metabolic pathway, thereby decreasing its own production.
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Which of the following is true regarding competitive and noncompetitive inhibition?
I. Both can be overcome by increasing the substrate concentration
II. Competitive inhibition induces changes to the active site
III. Noncompetitive inhibition has no effect on the enzyme affinity for substrates
Which of the following is true regarding competitive and noncompetitive inhibition?
I. Both can be overcome by increasing the substrate concentration
II. Competitive inhibition induces changes to the active site
III. Noncompetitive inhibition has no effect on the enzyme affinity for substrates
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Statement I is false because increasing the substrate concentration will only help overcome competitive inhibition. Noncompetitive inhibition can only be overcome if the inhibitor is removed from the enzyme.
Statement II is also false because competitive inhibitors do not change the active site. They bind to the active site and prevent substrates from binding. Noncompetitive inhibitors bind elsewhere on the enzyme and alter the shape of the active site, thereby preventing substrate binding.
Statement III is true because noncompetitive inhibition does not affect the enzyme affinity for substrates. The enzyme still has the same affinity, but the substrates can’t bind because of the altered active site.
Statement I is false because increasing the substrate concentration will only help overcome competitive inhibition. Noncompetitive inhibition can only be overcome if the inhibitor is removed from the enzyme.
Statement II is also false because competitive inhibitors do not change the active site. They bind to the active site and prevent substrates from binding. Noncompetitive inhibitors bind elsewhere on the enzyme and alter the shape of the active site, thereby preventing substrate binding.
Statement III is true because noncompetitive inhibition does not affect the enzyme affinity for substrates. The enzyme still has the same affinity, but the substrates can’t bind because of the altered active site.
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An antibiotic binds an enzyme, causing it to produce substrate C of a metabolic pathway instead of substrate A of the same pathway. Substrate C ultimately inhibits the enzyme in the normal course of the pathway.
In this metabolic pathway, Substrate C is acting as a(n) .
An antibiotic binds an enzyme, causing it to produce substrate C of a metabolic pathway instead of substrate A of the same pathway. Substrate C ultimately inhibits the enzyme in the normal course of the pathway.
In this metabolic pathway, Substrate C is acting as a(n) .
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Negative feedback interrupts a metabolic pathways by producing a substrate that inhibits enzymes in the beginning steps of the metabolic cycle. If a chemical is "mimicking" substrate C or causing Substrate C to be produced before other steps in a cycle, the enzyme is inhibited by the excess of substrate C thus the pathway can not continue. Most such molecules are proteins that interact with enzymes.
Negative feedback interrupts a metabolic pathways by producing a substrate that inhibits enzymes in the beginning steps of the metabolic cycle. If a chemical is "mimicking" substrate C or causing Substrate C to be produced before other steps in a cycle, the enzyme is inhibited by the excess of substrate C thus the pathway can not continue. Most such molecules are proteins that interact with enzymes.
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Substrates formed downstream in a metabolic pathway that act to increase the progression of that metabolic pathway are said to exhibit a mechanism.
Substrates formed downstream in a metabolic pathway that act to increase the progression of that metabolic pathway are said to exhibit a mechanism.
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A substrate that acts as a "positive motivator" of, or to enhance a metabolic pathway, is also known as a positive feedback regulator or a substance that has a positive feedback mechanism.
A substrate that acts as a "positive motivator" of, or to enhance a metabolic pathway, is also known as a positive feedback regulator or a substance that has a positive feedback mechanism.
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You are reading about the functions of a unique chemical compound. This compound works on enzymes throughout the body by altering the shape of the enzyme without blocking the active site. This compound functions via which mechanism?
You are reading about the functions of a unique chemical compound. This compound works on enzymes throughout the body by altering the shape of the enzyme without blocking the active site. This compound functions via which mechanism?
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Noncompetitive inhibition is a type of enzymatic alteration that results in changes to enzymatic function without alterations to the active site. If the active site was to be blocked, this compound would function via competitive inhibition. The other terms do not describe any type of enzymatic inhibition process in the human body. Be able to distinguish the difference between competitive and noncompetitive inhibition.
Noncompetitive inhibition is a type of enzymatic alteration that results in changes to enzymatic function without alterations to the active site. If the active site was to be blocked, this compound would function via competitive inhibition. The other terms do not describe any type of enzymatic inhibition process in the human body. Be able to distinguish the difference between competitive and noncompetitive inhibition.
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The induced fit model better explains enzyme substrate binding than does the lock and key model. The induced fit model explains which of the following, that is not explained by the lock and key model
The induced fit model better explains enzyme substrate binding than does the lock and key model. The induced fit model explains which of the following, that is not explained by the lock and key model
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The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit. The induced fit model accounts for the broad specificity of enzymes as the active site is not rigid, but can undergo a conformational change to better fit the substrate binding.
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit. The induced fit model accounts for the broad specificity of enzymes as the active site is not rigid, but can undergo a conformational change to better fit the substrate binding.
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This model of enzyme and substrate interaction posits that the active site of the enzyme undergoes conformational change when the correct substrate binds
This model of enzyme and substrate interaction posits that the active site of the enzyme undergoes conformational change when the correct substrate binds
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The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
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The lock and key model of enzyme substrate binding posits that
The lock and key model of enzyme substrate binding posits that
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The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
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Which model of enzyme substrate binding posits that there is a transition state that develops before the reactants undergo change
Which model of enzyme substrate binding posits that there is a transition state that develops before the reactants undergo change
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The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit.
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Which is NOT true of the lock and key model of enzyme substrate bonding?
Which is NOT true of the lock and key model of enzyme substrate bonding?
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The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit. The induced fit model does not account for a transition state during which the shape of the active site changes to better fit the substrate.
The lock and key model states that the active site of an enzyme precisely fits a specific substrate. The induced fit model states that the active site of an enzyme will undergo a conformational change when binding a substrate, to improve the fit. The induced fit model does not account for a transition state during which the shape of the active site changes to better fit the substrate.
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