The Candid Test On Microbiology

Approved & Edited by ProProfs Editorial Team
The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.
Learn about Our Editorial Process
| By Andreazza
A
Andreazza
Community Contributor
Quizzes Created: 12 | Total Attempts: 6,889
Questions: 68 | Attempts: 171

SettingsSettingsSettings
Microbiology Quizzes & Trivia

Microbiology includes fundamental research on the biochemistry, physiology, cell biology, ecology, evolution and clinical aspects of microorganisms, including the host response to these agents. One gets to understand how the cells in living things operate. Have you just covered chapter 9 on biology? Take up the candid test on biology below and refresh your memory.


Questions and Answers
  • 1. 

    __________ reactions capture energy from the organisms' energy source.  

    Explanation
    Catabolic reactions refer to the metabolic processes that break down larger molecules into smaller ones, releasing energy in the process. These reactions capture energy from the organisms' energy source, such as food or stored molecules, and convert it into a usable form for the cell. This energy is then used for various cellular activities, including growth, movement, and reproduction. Overall, catabolic reactions play a crucial role in providing energy for the organism's survival and functioning.

    Rate this question:

  • 2. 

    _________ is the total of all chemical reactions occurring in the cell.  

    Explanation
    Metabolism refers to the collective set of chemical reactions that take place within a cell. These reactions are responsible for various processes such as energy production, nutrient breakdown, and waste elimination. Metabolism can be divided into two main categories: catabolism, which involves the breakdown of molecules to release energy, and anabolism, which involves the synthesis of molecules using energy. Together, these reactions ensure the proper functioning and maintenance of the cell.

    Rate this question:

  • 3. 

    ________ reactions build new organic molecules from smaller inorganic and organic compounds.  

    Explanation
    Anabolic reactions refer to the metabolic processes that build or synthesize larger organic molecules from smaller inorganic or organic compounds. These reactions require energy input and are essential for growth, repair, and maintenance of cells and tissues. Examples of anabolic reactions include protein synthesis, DNA replication, and the formation of complex carbohydrates and lipids.

    Rate this question:

  • 4. 

    Cells carry out three major types of work; which of the following involves the synthesis of macromolecules as well as the breakdown of substances for their energy?  

    • A.

      Chemical work

    • B.

      Transport work

    • C.

      Mechanical work

    • D.

      None of the above

    Correct Answer
    A. Chemical work
    Explanation
    Chemical work involves the synthesis of macromolecules as well as the breakdown of substances for their energy. This type of work is essential for the cell to maintain its structure and function. It includes processes such as protein synthesis, DNA replication, and cellular respiration. Through chemical work, cells are able to build and break down molecules to support various cellular activities and maintain homeostasis.

    Rate this question:

  • 5. 

    Cells carry out three major types of work; which of the following involves nutrient uptake and waste elimination?  

    • A.

      Chemical work

    • B.

      Transport work

    • C.

      Mechanical work

    • D.

      None of the above

    Correct Answer
    B. Transport work
    Explanation
    Transport work involves the uptake of nutrients and the elimination of waste by cells. This process includes the movement of molecules across cell membranes, such as the transport of nutrients from the extracellular environment into the cell and the removal of waste products from the cell. Transport work is essential for maintaining the proper functioning and homeostasis of cells.

    Rate this question:

  • 6. 

    Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells?  

    • A.

      Chemical work

    • B.

      Transport work

    • C.

      Mechanical work

    • D.

      None of the above

    Correct Answer
    C. Mechanical work
    Explanation
    Mechanical work involves the energy needed for cell motility and the movement of structures within cells. This type of work includes activities such as muscle contraction, cell division, and the movement of organelles within the cell. Chemical work refers to the energy needed for chemical reactions, while transport work involves the energy required for the movement of molecules across cell membranes.

    Rate this question:

  • 7. 

    In thermodynamic studies, energy changes are analyzed in a collection of matter called a __________. All other matter in the universe is called the __________. (answer, answer)  

    Correct Answer
    system, surroundings, system, surrounding
    Explanation
    In thermodynamic studies, the energy changes are analyzed in a collection of matter called a system. This refers to the specific portion of matter that is being studied or analyzed. On the other hand, all other matter in the universe, which is not part of the system, is referred to as the surroundings. The surroundings can interact with the system and exchange energy with it. Therefore, the correct answers are system and surroundings, as they represent the distinct components in the analysis of energy changes in thermodynamics.

    Rate this question:

  • 8. 

    __________ is the science that analyzes energy changes in a collection of matter.  

    Correct Answer
    Thermodynamics
    Explanation
    Thermodynamics is the science that analyzes energy changes in a collection of matter. It studies how energy is transferred between different forms and how it affects the behavior of matter. This includes the study of heat, work, and energy conversion in various systems. Thermodynamics is essential in understanding and predicting the behavior of physical systems, such as engines, refrigerators, and chemical reactions. It provides a framework for understanding the principles and laws that govern energy transfer and transformation, making it a fundamental field in science and engineering.

    Rate this question:

  • 9. 

    Energy can be redistributed within a collection of matter (called a system) or can be redistributed between the system and its surroundings.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Energy can indeed be redistributed within a system or between the system and its surroundings. This means that energy can be transferred from one part of the system to another, or between the system and its environment. This redistribution of energy is a fundamental concept in thermodynamics and is observed in various processes, such as heat transfer, work done, and energy conversion. Therefore, the statement is true.

    Rate this question:

  • 10. 

    __________ is a measure of the randomness or disorder of a system.  

    • A.

      Entropy

    • B.

      Enthalpy

    • C.

      Free energy

    • D.

      Synergy

    Correct Answer
    A. Entropy
    Explanation
    Entropy is a measure of the randomness or disorder of a system. It quantifies the number of possible arrangements or states that a system can have. A system with high entropy is considered to be more disordered and has more possible arrangements, while a system with low entropy is considered to be more ordered and has fewer possible arrangements. Entropy is widely used in the fields of thermodynamics, information theory, and statistical mechanics to describe the behavior and characteristics of physical and information systems.

    Rate this question:

  • 11. 

    The __________ law of thermodynamics states that physical and chemical processes occur in such a way that randomness (disorder) increases to a maximum.  

    • A.

      First

    • B.

      Second

    • C.

      Third

    • D.

      Fourth

    Correct Answer
    B. Second
    Explanation
    The second law of thermodynamics states that physical and chemical processes occur in such a way that randomness (disorder) increases to a maximum. This law is based on the concept of entropy, which is a measure of the disorder or randomness of a system. According to the second law, in any spontaneous process, the total entropy of the system and its surroundings always increases. This means that over time, systems tend to become more disordered and random.

    Rate this question:

  • 12. 

    The __________ law of thermodynamics states that energy can be neither created nor destroyed.  

    • A.

      First

    • B.

      Second

    • C.

      Third

    • D.

      Fourth

    Correct Answer
    A. First
    Explanation
    The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, but it can be transferred or converted from one form to another. This principle is based on the understanding that energy is a constant in a closed system, and any energy gained or lost by the system must come from or go to its surroundings.

    Rate this question:

  • 13. 

    The amount of heat energy needed to raise 1 gram of water from 14.5C to 15.5C is called a(n)  

    • A.

      Joule

    • B.

      Calorie

    • C.

      Erg

    • D.

      Thermal unit

    Correct Answer
    B. Calorie
    Explanation
    The amount of heat energy needed to raise 1 gram of water from 14.5C to 15.5C is called a calorie. A calorie is a unit of energy commonly used in the field of thermodynamics and is defined as the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.

    Rate this question:

  • 14. 

    A reaction in which the forward rate is equal to the reverse rate is said to be at __________.  

    Correct Answer
    equilibrium
    Explanation
    When the forward rate of a reaction is equal to the reverse rate, it means that the reaction is occurring at a constant rate in both directions. This indicates that the concentrations of reactants and products are not changing over time. Such a state is known as equilibrium, where there is a balance between the forward and reverse reactions. At equilibrium, the overall concentration of the reactants and products remains constant, and there is no net change in the system.

    Rate this question:

  • 15. 

    The numerical value of the free energy change indicates how fast a reaction will reach equilibrium.  

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    The numerical value of the free energy change does not indicate how fast a reaction will reach equilibrium. Instead, it indicates the direction in which the reaction will proceed, either towards products (negative ΔG) or towards reactants (positive ΔG). The speed at which a reaction reaches equilibrium is determined by factors such as temperature, concentration, and catalysts.

    Rate this question:

  • 16. 

    __________ is the total energy change that accompanies a chemical reaction.  

    • A.

      Entropy

    • B.

      Enthalpy

    • C.

      Free energy

    • D.

      Synergy

    Correct Answer
    B. Enthalpy
    Explanation
    Enthalpy is the correct answer because it refers to the total energy change that occurs during a chemical reaction. It takes into account both the heat absorbed or released and the work done by the system. Entropy refers to the degree of disorder in a system, free energy is the energy available to do work, and synergy refers to the combined effect of multiple factors working together.

    Rate this question:

  • 17. 

    For the reaction A + B C + D, the equilibrium constant (Keq) is defined as  

    • A.

      [A][B]/[C][D]

    • B.

      [C][D]/[A][B]

    • C.

      [A][D]/[B][C]

    • D.

      [B][C]/[A][D]

    Correct Answer
    B. [C][D]/[A][B]
    Explanation
    The equilibrium constant (Keq) is defined as the ratio of the concentrations of the products (C and D) to the concentrations of the reactants (A and B) raised to their respective stoichiometric coefficients. Therefore, the correct answer is [C][D]/[A][B], as it represents the correct ratio of product concentrations to reactant concentrations in the equilibrium constant expression.

    Rate this question:

  • 18. 

    The change in __________ is the amount of energy in a system that is available to do work.  

    • A.

      Entropy

    • B.

      Enthalpy

    • C.

      Free energy

    • D.

      Synergy

    Correct Answer
    C. Free energy
    Explanation
    Free energy is the correct answer because it refers to the amount of energy in a system that is available to do work. It is a measure of the system's ability to undergo spontaneous change and perform useful work. Entropy, on the other hand, is a measure of the disorder or randomness in a system. Enthalpy is the total heat content of a system. Synergy refers to the combined effect of two or more entities working together to produce a greater effect than they could individually.

    Rate this question:

  • 19. 

    The most commonly used practical form of energy used in cells is adenosine diphosphate.  

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    The most commonly used practical form of energy used in cells is adenosine triphosphate (ATP), not adenosine diphosphate (ADP). ATP is a high-energy molecule that provides energy for cellular processes. ADP is a lower-energy molecule that is converted into ATP through the addition of a phosphate group, allowing it to store and release energy. Therefore, the correct answer is false.

    Rate this question:

  • 20. 

    A reaction that releases energy is __________.  

    • A.

      Exergonic

    • B.

      Endergonic

    • C.

      Impossible

    • D.

      None of the choices

    Correct Answer
    A. Exergonic
    Explanation
    An exergonic reaction is a reaction that releases energy. This means that the products of the reaction have less energy than the reactants, and the excess energy is released in the form of heat or light. In contrast, an endergonic reaction requires an input of energy in order to proceed. Therefore, the correct answer is exergonic.

    Rate this question:

  • 21. 

    Some endergonic reactions can be made to proceed forward if they are coupled to hydrolysis of one or more of the phosphates of ATP.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Endergonic reactions require an input of energy to proceed, and coupling them to the hydrolysis of ATP provides the necessary energy. ATP is a high-energy molecule that can release energy when its phosphate bonds are broken. By coupling the endergonic reaction to ATP hydrolysis, the energy released from ATP can be used to drive the endergonic reaction forward. Therefore, it is true that some endergonic reactions can be made to proceed forward by coupling them to the hydrolysis of ATP.

    Rate this question:

  • 22. 

    Cells must efficiently transfer energy from their energy-trapping systems to the systems actually carrying out work and also use various metabolic processes to replace the energy used in doing work. This is called the __________. (2 words)  

    Correct Answer
    energy cycle
    Explanation
    The term "energy cycle" refers to the process in which cells efficiently transfer energy from their energy-trapping systems to the systems that carry out work. It also involves the utilization of various metabolic processes to replenish the energy that is consumed during the performance of work. The energy cycle is essential for the functioning and survival of cells, as it ensures that energy is effectively utilized and replenished in order to sustain cellular activities.

    Rate this question:

  • 23. 

    In order for the cell to be able to input energy into necessary endergonic reactions, energygenerating processes such as photosynthesis, fermentation, and respiration are used to produce __________.  

    Correct Answer
    ATP
    Explanation
    Energy-generating processes such as photosynthesis, fermentation, and respiration are used to produce ATP. ATP (adenosine triphosphate) is a molecule that stores and releases energy in cells. It is the primary source of energy for cellular processes, including endergonic reactions. ATP is produced through the breakdown of molecules like glucose during cellular respiration or through the conversion of light energy during photosynthesis. It is then used by cells to power various biological processes, making it essential for the cell to input energy into necessary reactions.

    Rate this question:

  • 24. 

    An chemical reaction that requires an input of energy in order to proceed is __________.  

    • A.

      Exergonic

    • B.

      Endergonic

    • C.

      Impossible

    • D.

      None of the choices

    Correct Answer
    B. Endergonic
    Explanation
    An endergonic chemical reaction is one that requires an input of energy in order to proceed. In this type of reaction, the products have a higher energy level than the reactants, and the reaction cannot occur spontaneously without the addition of external energy.

    Rate this question:

  • 25. 

    The __________ is the electron acceptor in a redox reaction.  

    • A.

      Reductant

    • B.

      Oxidant

    • C.

      Enzyme

    • D.

      Product

    Correct Answer
    B. Oxidant
    Explanation
    In a redox reaction, the oxidant is the species that accepts electrons and gets reduced. It is responsible for causing the oxidation of another species by removing electrons from it. Therefore, the oxidant is the electron acceptor in a redox reaction.

    Rate this question:

  • 26. 

    The __________ is the electron donor in a redox reaction.  

    • A.

      Reductant

    • B.

      Oxidant

    • C.

      Enzyme

    • D.

      Product

    Correct Answer
    A. Reductant
    Explanation
    In a redox reaction, the reductant is the substance that donates electrons, causing another substance to be reduced. The oxidant, on the other hand, accepts these electrons and gets reduced itself. Therefore, the reductant is the electron donor in a redox reaction. Enzymes are biological catalysts that facilitate chemical reactions, while products are the substances formed as a result of a reaction.

    Rate this question:

  • 27. 

    The standard reduction potential of a redox reaction is a measure of the tendency of the __________ to __________ electrons.  

    • A.

      Reductant; gain

    • B.

      Reductant; lose

    • C.

      Oxidant; gain

    • D.

      Oxidant; lose

    Correct Answer
    B. Reductant; lose
    Explanation
    The standard reduction potential of a redox reaction is a measure of the tendency of the reductant to lose electrons. This means that the reductant has a higher tendency to undergo oxidation, which involves losing electrons. The higher the standard reduction potential, the more likely the reductant is to lose electrons and be oxidized.

    Rate this question:

  • 28. 

    The equilibrium constant for a redox reaction is called the standard reduction potential.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    The explanation for the given correct answer is that the equilibrium constant for a redox reaction is indeed called the standard reduction potential. This is because the standard reduction potential is a measure of the tendency of a species to gain electrons and undergo reduction in a redox reaction. It is represented by the symbol E° and is used to determine the direction and feasibility of a redox reaction. Therefore, it is true that the equilibrium constant for a redox reaction is called the standard reduction potential.

    Rate this question:

  • 29. 

    Which of the following is used as an electron carrier by living organisms?  

    • A.

      NAD+

    • B.

      NADP+

    • C.

      Ubiquinone

    • D.

      All of the choices

    Correct Answer
    D. All of the choices
    Explanation
    All of the choices are used as electron carriers by living organisms. NAD+ and NADP+ are coenzymes that play a crucial role in redox reactions, transferring electrons from one molecule to another. Ubiquinone, also known as coenzyme Q, is a lipid-soluble molecule that shuttles electrons between various protein complexes in the electron transport chain. Therefore, all three options serve as electron carriers in different metabolic pathways.

    Rate this question:

  • 30. 

    The electron transport chain is based on the principle that redox couples with more positive reduction potentials will donate electrons to couples with more negative potentials.  

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    The explanation for the correct answer is that the electron transport chain is based on the principle that redox couples with more negative reduction potentials will donate electrons to couples with more positive potentials, not the other way around. This is because electrons flow from a higher energy state to a lower energy state, so the redox couples with more negative reduction potentials have a higher energy and are able to donate electrons.

    Rate this question:

  • 31. 

    One of the components used during photosynthetic electron transport is ferredoxin, a nonheme iron protein.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    During photosynthetic electron transport, ferredoxin is indeed one of the components used. Ferredoxin is a nonheme iron protein that plays a crucial role in transferring electrons from photosystem I to various enzymes and carriers in the electron transport chain. This process is essential for the conversion of light energy into chemical energy during photosynthesis. Therefore, the statement "One of the components used during photosynthetic electron transport is ferredoxin, a nonheme iron protein" is true.

    Rate this question:

  • 32. 

    Electron transport molecules that only transfer electrons include  

    • A.

      Ubiquinone

    • B.

      NADP

    • C.

      FAD

    • D.

      Ferredoxin

    Correct Answer
    D. Ferredoxin
    Explanation
    Electron transport molecules are responsible for transferring electrons during cellular respiration. Ubiquinone, NADP, FAD, and ferredoxin are all examples of electron transport molecules. However, only ferredoxin exclusively transfers electrons. Ubiquinone, NADP, and FAD also have other functions in cellular metabolism. Therefore, ferredoxin is the correct answer as it is the only electron transport molecule that solely transfers electrons.

    Rate this question:

  • 33. 

    Which of the following is not true about enzymes?  

    • A.

      Enzymes are catalysts that speed up reactions.

    • B.

      Enzymes are proteins that can be denatured by changes in pH or temperature.

    • C.

      Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates.

    • D.

      All of the choices

    Correct Answer
    D. All of the choices
    Explanation
    Enzymes are catalysts that speed up reactions. Enzymes are proteins that can be denatured by changes in pH or temperature. Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates. Therefore, the statement "all of the choices" is not true about enzymes because it implies that all the statements listed are false, which is incorrect.

    Rate this question:

  • 34. 

    Disruption of an enzyme's structure with loss of activity caused by extremes of pH, temperature, or other factors is called _________.  

    Correct Answer
    denaturation
    Explanation
    Denaturation refers to the disruption of an enzyme's structure, resulting in the loss of its activity. This can be caused by various factors such as extremes of pH, temperature, or other environmental conditions. When an enzyme is denatured, its shape is altered, which affects its ability to bind to substrates and catalyze reactions. Denaturation can be reversible or irreversible, depending on the extent of structural changes.

    Rate this question:

  • 35. 

    A molecule that binds to an enzyme at a location other than the active site and thereby alters the enzyme's shape, making it inactive or less active is a(n) __________ inhibitor.  

    Correct Answer
    noncompetitive, non competitive, non-competitive
    Explanation
    A noncompetitive inhibitor is a molecule that binds to an enzyme at a location other than the active site. This binding causes a change in the enzyme's shape, which in turn makes the enzyme inactive or less active. Therefore, the correct answer is noncompetitive.

    Rate this question:

  • 36. 

    A molecule that binds noncovalently to an enzyme at the active site and thereby prevents a substrate from binding and reacting is a(n) __________ inhibitor.  

    Correct Answer
    competitive
    Explanation
    A competitive inhibitor is a molecule that binds noncovalently to an enzyme at the active site, preventing a substrate from binding and reacting. This type of inhibitor competes with the substrate for the active site, as they have similar structures and can both bind to the enzyme. However, the competitive inhibitor does not undergo a chemical reaction with the enzyme and can be displaced by increasing the substrate concentration.

    Rate this question:

  • 37. 

    The molecules formed by an enzyme-catalyzed reaction are called __________.  

    Correct Answer
    products
    Explanation
    In an enzyme-catalyzed reaction, the reactants are converted into different molecules known as products. These products are the result of the enzyme facilitating the reaction by lowering the activation energy required for the reaction to occur. Enzymes act as catalysts, speeding up chemical reactions without being consumed in the process. Therefore, the correct answer is "products."

    Rate this question:

  • 38. 

    The reacting molecules in an enzyme-catalyzed reaction are called __________.  

    Correct Answer
    substrates
    Explanation
    In an enzyme-catalyzed reaction, the molecules that undergo a chemical reaction are called substrates. Enzymes are biological catalysts that speed up chemical reactions by binding to the substrates and facilitating the conversion of reactants into products. The substrates bind to the active site of the enzyme, where the reaction takes place. This interaction between the enzyme and substrates allows for the efficient and specific conversion of substrates into products.

    Rate this question:

  • 39. 

    The __________ __________(km) is the substrate concentration needed for an enzyme to achieve half maximal velocity.  

    Correct Answer
    Michaelis constant
    Explanation
    The Michaelis constant (Km) is a measure of the substrate concentration required for an enzyme to reach half of its maximum velocity. It represents the affinity of the enzyme for its substrate, with a lower Km indicating a higher affinity. In other words, the Km value determines how quickly the enzyme can convert substrate into product at different substrate concentrations.

    Rate this question:

  • 40. 

    A complex formed during a reaction that resembles both the substrates and the products is called the __________ state complex.  

    Correct Answer
    transition
    Explanation
    The correct answer is "transition". In a chemical reaction, a transition state complex is a short-lived and highly unstable intermediate state that forms during the conversion of reactants into products. It resembles both the starting materials (substrates) and the final products. The transition state complex represents the highest energy point along the reaction pathway and is crucial for understanding the kinetics and mechanism of the reaction.

    Rate this question:

  • 41. 

    Each enzyme normally has specific pH and temperature optima at which they function best.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Enzymes are biological catalysts that speed up chemical reactions in living organisms. Each enzyme has a specific pH and temperature range at which it functions optimally. This is because the structure and activity of enzymes are influenced by their environment. Deviating from the optimal pH or temperature can denature the enzyme, affecting its shape and ability to catalyze reactions efficiently. Therefore, it is true that each enzyme has specific pH and temperature optima at which they function best.

    Rate this question:

  • 42. 

    The Michaelis constant (Km) of an enzyme is the substrate concentration that produces maximum velocity.  

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    The Michaelis constant (Km) of an enzyme is NOT the substrate concentration that produces maximum velocity. Instead, Km represents the substrate concentration at which the enzyme reaches half of its maximum velocity. Therefore, the given statement is false.

    Rate this question:

  • 43. 

    Enzyme activity can be greatly affected by the pH and the temperature of the environment in which the enzyme must function.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Enzyme activity is indeed greatly affected by the pH and temperature of the environment in which the enzyme functions. Enzymes are sensitive to changes in pH because they have an optimal pH range at which they work most efficiently. Deviating from this range can denature the enzyme and decrease its activity. Similarly, enzymes have an optimal temperature range at which they function best. Extreme temperatures can also denature the enzyme and affect its activity. Therefore, it is true that pH and temperature can have a significant impact on enzyme activity.

    Rate this question:

  • 44. 

    When the amount of enzyme present is held constant, the rate of a reaction will continue to increase as long as the substrate concentration increases.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    The statement is true because the rate of a reaction depends on the concentration of the substrate. As the substrate concentration increases, there are more substrate molecules available for the enzyme to react with, leading to an increase in the rate of the reaction. However, once the enzyme becomes saturated with substrate molecules, increasing the substrate concentration further will not increase the rate of the reaction.

    Rate this question:

  • 45. 

    Enzymes increase the rate of a reaction but do not alter equilibrium constants.  

    • A.

      True

    • B.

      False

    Correct Answer
    A. True
    Explanation
    Enzymes are catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur. They do this by providing an alternative reaction pathway with a lower activation energy. However, enzymes do not alter the equilibrium constants of the reactions they catalyze. Equilibrium constants depend on the difference in free energy between the reactants and products and are determined by the thermodynamics of the reaction. Enzymes do not affect the thermodynamics or the equilibrium position of a reaction, they only accelerate the rate at which equilibrium is reached. Therefore, the statement that enzymes increase the rate of a reaction but do not alter equilibrium constants is true.

    Rate this question:

  • 46. 

    Enzymes increase the rate of a reaction by increasing molecular motion, thereby providing kinetic energy to drive the reaction.  

    • A.

      True

    • B.

      False

    Correct Answer
    B. False
    Explanation
    Enzymes increase the rate of a reaction by lowering the activation energy required for the reaction to occur. They do not directly increase molecular motion or provide kinetic energy. Instead, enzymes act as catalysts by facilitating the formation of temporary enzyme-substrate complexes, which stabilize the transition state and allow the reaction to proceed more quickly. Therefore, the given statement is false.

    Rate this question:

  • 47. 

    Enzymes are usually named based on  

    • A.

      The substrates they act on.

    • B.

      Their molecular structure.

    • C.

      The type of reaction they catalyze.

    • D.

      All of the choices.

    • E.

      The substrates they act on and the type of reaction they catalyze.

    Correct Answer
    E. The substrates they act on and the type of reaction they catalyze.
    Explanation
    Enzymes are usually named based on the substrates they act on and the type of reaction they catalyze. This is because the name of an enzyme provides information about its function and specificity. By knowing the substrates an enzyme acts on and the type of reaction it catalyzes, scientists can easily identify and classify enzymes. This naming system helps in understanding the role and function of different enzymes in biochemical processes.

    Rate this question:

  • 48. 

    The most specific term usually used to describe a substance in a biological system that increases the rate of a reaction without being permanently changed by the reaction is a(n)  

    • A.

      Catalyzer

    • B.

      Catalyst

    • C.

      Enzyme

    • D.

      Rate increaser

    Correct Answer
    C. Enzyme
    Explanation
    An enzyme is a biological substance that increases the rate of a reaction without being permanently changed by the reaction. Enzymes work by binding to specific molecules, called substrates, and facilitating the conversion of these substrates into products. They do this by lowering the activation energy required for the reaction to occur, allowing it to happen more quickly. Enzymes are highly specific and can catalyze specific reactions in a biological system. Therefore, the most specific term used to describe a substance that increases the rate of a reaction without being permanently changed is an enzyme.

    Rate this question:

  • 49. 

    The substrate of an enzyme binds at the  

    • A.

      Affinity site

    • B.

      Active site

    • C.

      Determinative site

    • D.

      Reaction site

    Correct Answer
    B. Active site
    Explanation
    The active site is where the substrate binds to the enzyme. This is the specific region on the enzyme where the substrate molecule fits and undergoes a chemical reaction. The active site has a unique shape and chemical properties that allow it to bind with the substrate and facilitate the conversion of the substrate into a product. The binding of the substrate to the active site is crucial for the enzyme to carry out its catalytic function.

    Rate this question:

  • 50. 

    A complete enzyme that consists of a protein component and a nonprotein component is called a(n)  

    • A.

      Apoenzyme

    • B.

      Heteroenzyme

    • C.

      Holoenzyme

    • D.

      Multienzyme

    Correct Answer
    C. Holoenzyme
    Explanation
    A complete enzyme that consists of a protein component and a nonprotein component is called a holoenzyme. The protein component is called the apoenzyme, while the nonprotein component is called the cofactor or coenzyme. The holoenzyme is the active form of the enzyme and requires both the protein and nonprotein components to function properly.

    Rate this question:

Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 20, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Jun 02, 2012
    Quiz Created by
    Andreazza
Back to Top Back to top
Advertisement
×

Wait!
Here's an interesting quiz for you.

We have other quizzes matching your interest.