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30 Cards in this Set
- Front
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Which type of potential energy is stored in molecules of food and gasoline? Light Ionic Covalent Chemical Heat |
Chemical |
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Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of competitive inhibition. noncompetitive inhibition. feedback inhibition. positive feedback. irreversible inhibition. |
feedback inhibition. |
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A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child’s temperature. Which of the following statements offers the most logical explanation for this action? Elevated body temperature will increase reaction rates in the child’s cells and overload the limited number of enzymes found in the cell. Elevated body temperatures may denature enzymes. This would interfere with the cell’s abilities to catalyze various reactions. Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. Elevated body temperatures will have no effect on enzyme-mediated reactions. Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions. |
Elevated body temperatures may denature enzymes. This would interfere with the cell’s abilities to catalyze various reactions. |
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An enzyme is generally named by adding ______ to the end of the name of the ______. "-ose," cell in which it is found "-ase," cell in which it is found "-ose," substrate "-ase," substrate "-ase," coenzyme |
"-ase," substrate |
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Astrophysicists explain that eventually the sun will swell to become a red giant, engulf the earth and "burn out" with all forms of energy dispersing in a final "heat death." Compared with conditions today, the entropy of the universe then will _____. have increased greatly. have decreased greatly. remain the same because energy cannot be created or destroyed. have decreased minimally. not exist. |
have increased greatly. |
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Most of a cell's enzymes are ________. lipids proteins amino acids nucleic acids carbohydrates |
proteins |
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Which one of the following is true about the ATP molecule? It contains two phosphate groups. Extremely stable bonds link the second and third phosphate groups. It contains the six-carbon sugar hexose. It contains a nitrogenous base molecule called adenine. None of the choices are correct. |
It contains a nitrogenous base molecule called adenine. |
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The term "phosphorylation" refers to the use of an enzyme to break down ATP. transfer of a phosphate to a substrate - like ADP. taking away of phosphate molecules from enzymes. second law of thermodynamics relating to phosphorous function. subtraction of a phosphate from a substrate. |
transfer of a phosphate to a substrate - like ADP. |
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Two basic kinds of enzyme inhibitors are properly called ________. in-play and out-of-play allosteric and functionally active competitive and noncompetitive induced fit and active site cofactors and induced fit models |
competitive and noncompetitive |
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The active site of an enzyme is where the coenzyme is located. is a specific bulge or protuberance on an enzyme. is a groove or crevice on the structure of the enzyme. will react with only one substrate no matter how many molecules may resemble the shape of the substrate. rigidly resists any alteration of its shape. |
is a groove or crevice on the structure of the enzyme. |
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The processes of photosynthesis and cellular respiration are complementary. During these energy conversions, some energy is lost in the form of heat. created in the form of heat. used to create light. All of the choices are correct. None of the choices are correct. |
lost in the form of heat. |
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Which of the following is a coenzyme? zinc Vitamin B6 iron iodine hydrogen ions |
Vitamin B6 |
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Which one of the following processes is endergonic? the burning of wood the release of heat from the breakdown of glucose the synthesis of glucose from carbon dioxide and water the breakdown of glucose cellular respiration |
the synthesis of glucose from carbon dioxide and water |
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Which of the following organelles produces ATP? A. Golgi apparatus B. Mitochondria C. Lysosome D. Ribosome E. Both b and c are correct. |
Mitochondria |
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Which of the following is consistent with the laws of physics governing energy? When a liter of gasoline is burned in a car engine, 100% of its energy goes into moving the car along the road. You eat a "quarter-pounder" hamburger and assemble exactly a quarter-pound of additional body weight on your body. Eventually sunlight that is absorbed on the earth returns to space as dispersed heat. A calorie of sunlight becomes a calorie of plant tissue that, eaten by you, becomes a calorie of heat lost in muscle "power." Chemical bonds are a case of converting energy to matter; breaking the bonds converts matter to energy. |
Eventually sunlight that is absorbed on the earth returns to space as dispersed heat. |
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ATP is considered a high-energy compound because under cellular conditions, 7.3 kcal per mole of energy is released when a bond is broken between ______. the base adenine and the sugar ribose. the adenosine and the phosphate groups. the base adenine and the phosphate groups. the adenosine diphosphate and the third phosphate. All of the above bonds release energy as ATP is completely broken down. |
the adenosine diphosphate and the third phosphate. |
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Which statement describes the currently accepted theory of how an enzyme and its substrate fit together? As the product is released, the enzyme breaks down. The enzyme is like a key that fits into the substrate, which is like a lock. The active site is permanently changed by its interaction with the substrate. As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction. None of the choices are correct. |
As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction. |
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ATP is the energy currency of a cell produced by the destruction of ADP expended in the process of photosynthesis produced during the phosphorylation of any organic compound |
the energy currency of a cell |
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Life's primary source of energy is ____. food water heat ATP entropy |
ATP |
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When an enzyme catalyzes a reaction, it lowers the activation energy of the reaction. it raises the activation energy of the reaction. it becomes a product. it acts as a reactant. None of the choices are correct. |
it lowers the activation energy of the reaction. |
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Enzymes are _______. A. influenced by temperature B. influenced by pH C. not influenced by salinity D. both a and b E. All of the choices are correct. |
both a and b |
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Which statement about energy transformations is true? In energy transformations, energy is conserved or recycled. Living organisms decrease entropy in the universe as energy is transformed from light to chemical energy. Energy is constantly being created in the universe. Entropy is constantly increasing in the universe. Energy transformations decrease entropy in the universe. |
Entropy is constantly increasing in the universe. |
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Kinetic energy differs from chemical energy in that ______. kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement kinetic energy depends on the movement of atoms, whereas chemical energy depends on the movement of molecules kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules chemical energy is a particular form of kinetic energy |
kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules |
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According to __________, energy cannot be created or destroyed. Aristotle's first principle the first law of thermodynamics the second law of thermodynamics the third law of thermodynamics Einstein's law of relativity |
the first law of thermodynamics |
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Anything that prevents ATP formation will most likely result in cell death. force the cell to rely on lipids for energy. result in the conversion of kinetic energy to potential energy. force the cell to rely on ADP for energy. have no effect on the cell. |
result in cell death |
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Which of the following is true of an energy barrier? It is the amount of energy that must be produced by the reactants to end a chemical reaction. It is higher than the activation energy of a reaction. It prevents the spontaneous breakdown of molecules in the cell. It can only be overcome with the use of enzymes. It may place chemical groups of the active site in position to catalyze the reaction. |
It prevents the spontaneous breakdown of molecules in the cell. |
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The second law of thermodynamics states that____________. energy can be transformed into matter and, because of this, we can get something for nothing. energy can be destroyed only during nuclear reactions, such as those that occur inside the sun. if energy is gained by one region of the universe, another place in the universe also must gain energy to maintain the balance of nature. energy tends to become increasingly dispersed and unusable. |
energy tends to become increasingly dispersed and unusable. |
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Which one of the following is false? An enzyme's function depends on its three-dimensional shape. Enzymes are very specific for certain substrates. Enzymes are used up in chemical reactions. Enzymes emerge unchanged from the reactions they catalyze. An enzyme binds to its substrate at the enzyme's active site. |
Enzymes are used up in chemical reactions. |
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Coupling occurs when the energy released by an exergonic reaction is ______. used to drive another exergonic reaction. used to drive an endergonic reaction. lost as nonusable heat to the environment. used to decrease the entropy of the universe. All of the choices are correct. |
used to drive an endergonic reaction |
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A coenzyme is ____. an ionic cofactor that interacts with an enzyme to allow it to work. a protein cofactor that interacts with an enzyme to allow it to work. a nonprotein organic cofactor that interacts with an enzyme to allow it to work. an ionic cofactor that interacts with an enzyme to inhibit it. a protein cofactor that interacts with an enzyme to inhibit it. |
a nonprotein organic cofactor that interacts with an enzyme to allow it to work. |
