Test 2 Practice – Flashcards
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How do high temperatures speed chemical reactions?
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Heat causes the reactants to move faster and collide more often.
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What process below would speed up a reaction rate by decreasing the activation energy?
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Adding a catalyst
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Catalysts speed reactions mainly by ...
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lowering EA.
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Which of the following factors affect the process of a chemical reaction?
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Free energy changes
Substrate concentration
Temperature
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How do cells use ATP to raise the energy level of reaction substrates?
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The terminal phosphate of ATP is bound to the substrate.
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Why is ATP a good source of energy for biological reactions?
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Triphosphate chains are unstable.
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A reaction is said to be unfavorable if ...
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the free energy change of the reaction is positive and the reaction favors the reactants
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The reaction A → B is unfavorable by itself, but through energy-coupling, cells can use ATP to convert A into B. How is this done?
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The unfavorable reaction is replaced by two favorable reactions.
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How do cells replace the energy-rich ATP that is destroyed in energy-coupled reactions?
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Chloroplasts use light energy to synthesize ATP.
Mitochondria synthesize ATP using energy that's released by oxidizing sugars and fats.
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Which of the following can change the shape of an enzyme?
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phosphorylation
temperature
pH
