Enzymes - AP Biology
Card 0 of 722
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
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.
Compare your answer with the correct one above
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?
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.
Compare your answer with the correct one above
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) __________.
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.
Compare your answer with the correct one above
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.
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.
Compare your answer with the correct one above
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?
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.
Compare your answer with the correct one above
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
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.
Compare your answer with the correct one above
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
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.
Compare your answer with the correct one above
The lock and key model of enzyme substrate binding posits that
The lock and key model of enzyme substrate binding posits that
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.
Compare your answer with the correct one above
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
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.
Compare your answer with the correct one above
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?
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.
Compare your answer with the correct one above
How do enzymes speed up a reaction?
How do enzymes speed up a reaction?
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.
Compare your answer with the correct one above
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?
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.
Compare your answer with the correct one above
GLUT1 is a type of protein used to facilitate the transport of glucose across the plasma membrane. What protein classification accurately describes GLUT1?
GLUT1 is a type of protein used to facilitate the transport of glucose across the plasma membrane. What protein classification accurately describes GLUT1?
GLUT1 is a protein that allows glucose to pass into a cell through the membrane. Glucose is a large polar molecule, meaning that it will require a protein in order to diffuse across the membrane. GLUT1 must span the entire length of the plasma membrane in order to provide a "passage" for glucose to diffuse. As a result, GLUT1 is classified as an integral protein, or a protein that fully transverses the membrane.
Peripheral, or extrinsic proteins, are situated on the surfaces of membranes, and do not span across the bilayer. Enzymes catalyze biological reactions; GLUT1 is a transport protein, and does not catalyze any reactions.
GLUT1 is a protein that allows glucose to pass into a cell through the membrane. Glucose is a large polar molecule, meaning that it will require a protein in order to diffuse across the membrane. GLUT1 must span the entire length of the plasma membrane in order to provide a "passage" for glucose to diffuse. As a result, GLUT1 is classified as an integral protein, or a protein that fully transverses the membrane.
Peripheral, or extrinsic proteins, are situated on the surfaces of membranes, and do not span across the bilayer. Enzymes catalyze biological reactions; GLUT1 is a transport protein, and does not catalyze any reactions.
Compare your answer with the correct one above
Which of the following statements is not true concerning enzymes?
Which of the following statements is not true concerning enzymes?
Enzymes are biological catalysts that increase the rate of a chemical reaction. This is accomplished by lowering the activation energy for the reaction. Enzymes increase the rate of a reaction, but do NOT increase the amount of products formed in the reaction. They simply cause the products to be formed faster.
Enzymes are biological catalysts that increase the rate of a chemical reaction. This is accomplished by lowering the activation energy for the reaction. Enzymes increase the rate of a reaction, but do NOT increase the amount of products formed in the reaction. They simply cause the products to be formed faster.
Compare your answer with the correct one above
Which of the following is not a function of an enzyme?
Which of the following is not a function of an enzyme?
A catalyst speeds up the rate of a reaction by lowering the activation energy, which is caused by the high energy transition state. Enzymes are a class of catalyst specific to biological processes, accelerating these processes by lowering activation energy and transition state energy. Catalysts and enzymes may help reactions move faster, but they do not affect the final equilibrium amounts of reactants and products.
A catalyst speeds up the rate of a reaction by lowering the activation energy, which is caused by the high energy transition state. Enzymes are a class of catalyst specific to biological processes, accelerating these processes by lowering activation energy and transition state energy. Catalysts and enzymes may help reactions move faster, but they do not affect the final equilibrium amounts of reactants and products.
Compare your answer with the correct one above
Which of the following is not a common function of proteins?
Which of the following is not a common function of proteins?
While some proteins (such as histones) can pass down information from generation to generation, typically DNA is the macromolecule associated with encoding information.
Proteins commonly catalyze reactions. When these reactions occur in a biological organism, the proteins are considered enzymes. Proteins can also be embedded in cellular membranes, acting as channels or receptors to allow molecular transport. One protein, tubulin, is used to build cilia and flagella (as well as microtubules) that are essential to cell motility.
While some proteins (such as histones) can pass down information from generation to generation, typically DNA is the macromolecule associated with encoding information.
Proteins commonly catalyze reactions. When these reactions occur in a biological organism, the proteins are considered enzymes. Proteins can also be embedded in cellular membranes, acting as channels or receptors to allow molecular transport. One protein, tubulin, is used to build cilia and flagella (as well as microtubules) that are essential to cell motility.
Compare your answer with the correct one above
Which of the following biological molecules is most similar to proteins?
Which of the following biological molecules is most similar to proteins?
Proteins are organic molecules made of amino acids that are capable of interfacing with certain substrates and facilitating cellular activities. Enzymes are a sub-group of proteins that are used to speed up reactions within the body. Enzymatic proteins are essential to many biological and cellular processes, such as cellular respiration, transcription, and DNA replication.
Proteins are organic molecules made of amino acids that are capable of interfacing with certain substrates and facilitating cellular activities. Enzymes are a sub-group of proteins that are used to speed up reactions within the body. Enzymatic proteins are essential to many biological and cellular processes, such as cellular respiration, transcription, and DNA replication.
Compare your answer with the correct one above
At what pH does pepsin best function?
At what pH does pepsin best function?
Pepsin is an enzyme in the stomach that digests proteins. Because it is active in the stomach, which is highly acidic, pepsin best functions at a low pH between 2 and 2.5.
Pepsinogen is secreted by chief cells and converted into active pepsin after catalyzation by hydrochloric acid. The acid is secreted by parietal cells in response to gastrin secretion by G cells. After the stomach contents enter the duodenum of the small intestine, the acid is neutralized by bicarbonate secretions from the pancreas. This prevents the acid from damaging the walls of the small intestine.
Pepsin is an enzyme in the stomach that digests proteins. Because it is active in the stomach, which is highly acidic, pepsin best functions at a low pH between 2 and 2.5.
Pepsinogen is secreted by chief cells and converted into active pepsin after catalyzation by hydrochloric acid. The acid is secreted by parietal cells in response to gastrin secretion by G cells. After the stomach contents enter the duodenum of the small intestine, the acid is neutralized by bicarbonate secretions from the pancreas. This prevents the acid from damaging the walls of the small intestine.
Compare your answer with the correct one above
Amylase facilitates the breakdown of glycosidic bonds in carbohydrates. Which functional group will not be present in a molecule of amylase?
Amylase facilitates the breakdown of glycosidic bonds in carbohydrates. Which functional group will not be present in a molecule of amylase?
You should immediately realize that amylase is an enzyme because it ends in "-ase". Remember that enzymes are proteins; therefore they are made up of amino acids. All amino acids contain a carboxylic acid (-COOH), an amine (-NH2), and a hydrogen (-H) attached to the central carbon. Phosphate groups (-PO3) are more commonly found in lipids and nucleic acids, not in proteins. No amino acids contain phosphate groups, though phosphates can be added to certain amino acids to activate certain proteins and enzymes (phosphorylation).
You should immediately realize that amylase is an enzyme because it ends in "-ase". Remember that enzymes are proteins; therefore they are made up of amino acids. All amino acids contain a carboxylic acid (-COOH), an amine (-NH2), and a hydrogen (-H) attached to the central carbon. Phosphate groups (-PO3) are more commonly found in lipids and nucleic acids, not in proteins. No amino acids contain phosphate groups, though phosphates can be added to certain amino acids to activate certain proteins and enzymes (phosphorylation).
Compare your answer with the correct one above
What is the active site of an enzyme?
What is the active site of an enzyme?
Catalysts are molecules that are capable of increasing reaction speed. Enzymes are a particular subset of catalysts; enzymes are proteins that can aid in biological reactions and are crucial to many metabolic processes that occur in cells. Enzymes lower the activation energy of a given reaction, allowing the reaction to proceed faster. The active site of an enzyme is the region of the enzyme that can bind a substrate, when a substrate collides into the enzyme molecule. Joining of an enzyme and substrate results in a chemical reaction whereby the substrates are converted into products. The active site of an enzyme is specific to the substrate's shape, like a lock-and-key mechanism.
Catalysts are molecules that are capable of increasing reaction speed. Enzymes are a particular subset of catalysts; enzymes are proteins that can aid in biological reactions and are crucial to many metabolic processes that occur in cells. Enzymes lower the activation energy of a given reaction, allowing the reaction to proceed faster. The active site of an enzyme is the region of the enzyme that can bind a substrate, when a substrate collides into the enzyme molecule. Joining of an enzyme and substrate results in a chemical reaction whereby the substrates are converted into products. The active site of an enzyme is specific to the substrate's shape, like a lock-and-key mechanism.
Compare your answer with the correct one above