Questão 1
Questão
Reactions that release free energy are
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exergonic
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spontaneous
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endergonic
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endothermic
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both a and b
Questão 2
Questão
Enzymes speed up reactions by
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providing chemical energy to fuel a reaction
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lowering the activation energy necessary to initiate the reaction
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causing an endergonic reaction to become an exergonic reaction
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substituting one of the reactants necessary for the reaction
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none of the above
Questão 3
Questão
For the idealized reaction aA + bB === cC + dD, suppose that the equilibrium constant Keq, is 0.01. If the starting concentration for A,B,C, and D are 1 M each, what would you predict will happen based on the value of Keq?
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The forward reaction is favored
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The reverse reaction is favored
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The forward reaction is fast
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The reverse reaction is fast
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Both b and d are correct
Questão 4
Questão
Researchers analyzed a cell extract-- a mixture of molecules isolated from cells-- and studied a chemical reaction in which a carbohydrate was broken down into smaller molecules. When they added a protease to the cell extract, the discovered that the protease greatly inhibited the rate of the reaction. Based on this observation, you could conclude that the reaction is
Questão 5
Questão
In biological systems, ATP functions by
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providing the energy to drive endergonic reactions
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acting as an enzyme and lowering the activation energy of certain reactions
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adjusting the pH of solutions to maintain optimal conditions for enzyme activity
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regulating the speed at which endergonic reactions proceed
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interacting with enzymes as a cofactor to stimulate chemical reactions
Questão 6
Questão
In a chemical reaction, NADH is converted to NAD+ plus H+. W easy that NADH has been
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reduced
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phosphorylated
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oxidized
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decarboxylated
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methylated
Questão 7
Questão
Currently, scientists are identifying proteins that use ATP as an energy source by
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determining whether those proteins function in anabolic or catabolic reactions
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determine is the protein has a known ATP-binding site
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predicting the free energy necessary for the protein to function
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determining if the protein has an ATP synthase subunit
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all of the above
Questão 8
Questão
For a particular chemical reaction, an inhibitor raises the Km, but does not affect the Vmax. This inhibitor
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is a competitive inhibitor
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is a noncompetitive inhibitor
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binds to the active site of the enzyme
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binds to an allosteric site of the enzyme
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is a competitive inhibitor and binds to the active site of the enzyme
Questão 9
Questão
Which of the following is (are) key benefits of catabolic reactions?
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Recycling of organic building blocks
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Breakdown of organic molecules to obtain energy
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Synthesis of important polymers, such as polypeptides
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All of the above
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a and b only
Questão 10
Questão
Autophagy provides a way for cells to
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degrade entire organelles and cycle their components
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control the level of ATP
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engulf bacterial cells
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export unwanted organelles out of the cell
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inhibit the first enzyme in a metabolic pathway