Unit 3 Review Game Page 1

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1 Unit 3 Review Game Page 1 1 What best characterizes the role of TP in cellular metabolism? It is catabolized to carbon dioxide and water. The G associated with its hydrolysis is positive. The charge on the phosphate group of TP tends to make the molecule very water-soluble. The release of free energy during the hydrolysis of TP heats the surrounding environment. The free energy released by TP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate. 2 In general, the hydrolysis of TP drives cellular work by releasing heat. acting as a catalyst. changing to P and phosphate. lowering the free energy of the reaction. releasing free energy that can be coupled to other reactions. 3 Which of the following is NOT an example of the cellular work accomplished with the free energy derived from the hydrolysis of TP? mechanical work, such as the beating of cilia chemical work, such as the synthesis of new protein the production of heat, which raises the temperature of the cell transport work, such as the active transport of an ion into a cell all of the above 4 Which compound could be most easily modified to form TP? the amino acid tryptophan the monosaccharide ribose the nitrogenous base adenine the RN nucleotide adenosine the N nucleotide adenosine 5 Under most conditions, the supply of energy by catabolic pathways is regulated by the demand for energy by anabolic pathways. onsidering the role of TP formation and hydrolysis in energy coupling of anabolic and catabolic pathways, which of the following statements is most likely to be true? High levels of P act as an allosteric inhibitor of anabolic pathways. High levels of TP act as an allosteric activator of anabolic pathways. High levels of P act as an allosteric inhibitor of catabolic pathways. High levels of P act as an allosteric activator of catabolic pathways. High levels of TP act as an allosteric activator of catabolic pathways.

2 Unit 3 Review Game Page 2 6 n exergonic (spontaneous) reaction is a chemical reaction that is common in anabolic pathways. cannot occur outside of a living cell. leads to a decrease in the entropy of the universe. occurs only when an enzyme or other catalyst is present. releases energy when proceeding in the forward direction. 7 Which of the following correctly states the relationship between anabolic (typically endergonic) and catabolic (typically exergonic) pathways? The flow of energy between catabolic and anabolic pathways is reversible. atabolic pathways produce usable cellular energy by synthesizing more complex organic molecules. egradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways. nabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways. nergy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways. 8 Organisms are described as thermodynamically open systems. Which of the following statements is consistent with this description? Organisms acquire energy from their surroundings. ells cannot exchange materials with their environment. The metabolism of an organism is isolated from its surroundings. Heat produced by the organism is conserved in the organism and not lost to the environment. ecause energy must be conserved, organisms constantly recycle energy and thus need no input of energy. 9 chemical reaction is designated as exergonic rather than endergonic when it absorbs more energy. activation energy is required. activation energy exceeds net energy release. the products are less complex than the reactants. the potential energy of the products is less than the potential energy of the reactants. 10 What must be true if the reaction + + occurs spontaneously? The reaction must be endergonic. The H of the reaction must be positive. The G of the reaction must be negative. The difference between H and T S must be positive. ll of the above are true.

3 Unit 3 Review Game Page 3 11 The function of cellular respiration is to reduce O2. produce carbohydrates. extract O2 from the atmosphere. extract usable energy from glucose. synthesize macromolecules from monomers. 12 Most of the electron carriers (NH and FH2) that deliver electrons to the electron transport chain come from which of the following? glycolysis anabolic pathways the citric acid cycle oxidative phosphorylation substrate-level phosphorylation 13 In the overall process of glycolysis and cellular respiration, is oxidized and is reduced. TP... oxygen oxygen... TP glucose... TP glucose... oxygen carbon dioxide... water 14 In an experiment, mice were fed glucose (6H12O6) containing a small amount of radioactive carbon (carbon-14). The mice were closely monitored, and in a few minutes radioactive carbon atoms showed up in which compound? TP NH water oxygen gas carbon dioxide 15 chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to kill bacteria in people with infections. This is a bad idea because glycolysis can occur without the action of enzymes. glycolysis produces so little TP that the drug will have little effect. bacteria are prokaryotes; they usually don't need to perform glycolysis. human cells must also perform glycolysis; the drug might also kill humans. this step in the pathway of glycolysis can be skipped in bacteria, but not in humans.

4 Unit 3 Review Game Page 4 16 uring aerobic respiration, molecular oxygen (O2) is used for which of the following purposes? at the end of glycolysis to oxidize pyruvate as a source of O2 in every reaction that produces O2 at the end of the citric acid cycle to regenerate citric acid at the end of the electron transport chain to accept electrons and form H2O between glycolysis and the citric acid cycle to split a carbon from pyruvate, producing O2 17 How many molecules of TP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen? about 38 none of the above 18 Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step enables the cell to recycle N+. prevents pyruvate from accumulating. extracts a bit more energy from glucose. removes poisonous oxygen from the environment. enables the cell to make pyruvate into substances it can use. 19 Which part of the cellular catabolism of glucose both requires molecular oxygen (O2) and produces O2? glycolysis the citric acid cycle the electron transport chain the combination of glycolysis and the citric acid cycle the combination of the citric acid cycle and electron transport 20 If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result? The cells will consume glucose at an increased rate. The cells will not be able to carry out oxidative phosphorylation. The muscle cells will have more trouble making enough TP to meet their energy requirements. and are correct,, and are correct

5 Unit 3 Review Game Page 5 nswer Key : Unit 3 Review Game Question: nswer