CHAPTER 14 ENERGY GENERATION IN MITOCHONDRIA AND CHLOROPLASTS ALL ANSWERS 100% GUARANTEE GRADE A+

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14-1 The link between bond-forming reactions and membrane transport processes in the mitochondria is called . (a) chemiosmotic coupling (b) proton pumping (c) electron transfer (d) ATP synthesis ... 14-2 Describe how a standard flashlight battery can convert energy into useful work and explain how this is similar to the energy conversions in the mitochondria. 14-3 Modern eucaryotes depend on mitochondria to generate most of the cell’s ATP. How many molecules of ATP can a single molecule of glucose generate? (a) 30 (b) 2 (c) 20 (d) 36 14-4 The citric acid cycle generates NADH and FADH2, which are then used in the process of oxidative phosphorylation to make ATP. If the citric acid cycle (which does not use oxygen) and oxidative phosphorylation are separate processes, as they are, then why is it that the citric acid cycle stops almost immediately when O2 is removed? ANSWER W/O oxygen the chain wont be able to pass electrons. the cell runs out of NAD+ so NADH cannot be made in the CAC of the chain. 14-5 Indicate whether the following statements are true or false. If a statement is false, explain why it is false. A. The number and location of mitochondria within a cell can change, depending on the both the cell type and the amount of energy required. B. The inner mitochondrial membrane contains porins, which allow pyruvate to enter for use in the citric acid cycle. C. The inner mitochondrial membrane is actually a series of discrete flattened membrane-enclosed compartments called cristae, similar to what is seen in the Golgi apparatus. D. The intermembrane space of the mitochondria is chemically equivalent to the cytosol with respect to pH and the small molecules present. A: TRUE 14-6 In which of the four compartments of a mitochondrion are each of the following located? A. porin B. the mitochondrial genome C. citric acid cycle enzymes D. proteins of the electron-transport chain E. ATP synthase F. membrane transport protein for pyruvate SOLUTION A) porin: outer membrane B) mitochondrial DNA genome: matrix C) citric acid cycle enzymes: matrix D) proteins of the electron-transport chain: inner membrane E) ATP synthase: inner membrane F) membrane transport protein for pyruvate: inner membrane G) enzymes that phosphorylate other nucleotides (using ATP): intermembrane space 14-7 NADH contains a high-energy bond that, when cleaved, donates a pair of electrons to the electron-transport chain. What are the immediate products of this bond cleavage? (a) NAD+ + OH- (b) NAD+ + H- (c) NAD- + H+ (d) NAD + H 14-8 For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once. Mitochondria can use both pyruvate and fatty acids directly as fuel. NADH produced in the citric acid cycle donates electrons to the electron- transport chain. The citric acid cycle oxidizes acetyl groups and produces carbon dioxide as a waste product. oxygen acts as the final electron acceptor in the electron-transport chain. The synthesis of ATP in mitochondria is also known as oxidative phosphorylation . acetyl groups NADH carbon dioxide NADP+ chemiosmosis NADPH fatty acids oxidative phosphorylation glucose oxygen NAD+ pyruvate 14-9 Electron transport is coupled to ATP synthesis in mitochondria, in chloroplasts, and in the thermophilic bacterium Methanococcus. Which of the following is likely to affect the coupling of electron transport to ATP synthesis in all of these systems? (a) a potent inhibitor of cytochrome oxidase (b) the removal of oxygen (c) the absence of light (d) an ADP analogue that inhibits ATP synthase 14-10 Stage 1 of oxidative phosphorylation requires the movement of electrons along the electron-transport chain coupled to the pumping of protons into the intermembrane space. What is the final result of these electron transfers? (a) OH- is oxidized to O2. (b) Pyruvate is oxidized to CO2. (c) O2 is reduced to H2O. (d) H- is converted to H2. 14-11 Which component of the electron-transport chain is required to combine the pair of electrons with molecular oxygen? (a) cytochrome c (b) cytochrome b-c1 complex (c) ubiquinone (d) cytochrome c oxidase 14-12 For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below. Not all words or phrases will be used; each word or phrase should be used only once. NADH donates electrons to the of the three respiratory enzyme complexes in the mitochondrial electron-transport chain. is a small protein that acts as a mobile electron carrier in the respiratory chain. transfers electrons to oxygen. Electron transfer in the chain occurs in a series of reactions. The first mobile electron carrier in the respiratory chain is . cytochrome c plastoquinone cytochrome oxidase reduction first second NADH dehydrogenase the cytochrome b-c1 complex oxidation third oxidation–reduction ubiquinone phosphorylation 14-13 In oxidative phosphorylation, ATP production is coupled to the events in the electron-transport chain. What is accomplished in the final electron transfer event in the electron-transport chain? (a) OH- is oxidized to O2. (b) Pyruvate is oxidized to CO2. (c) O2 is reduced to H2O. (d) NAD+ is reduced to NADH. 14-14 Which of the following statements is true? (a) Because the electrons in NADH are at a higher energy than the electrons in reduced ubiquinone, the NADH dehydrogenase complex can pump more protons than can the cytochrome b-c1 complex. (b) The pH in the mitochondrial matrix is higher than the pH in the intermembrane space. (c) The proton concentration gradient and the membrane potential across the inner mitochondrial membrane tend to work against each other in driving protons from the intermembrane space into the matrix. (d) The difference in proton concentration across the inner mitochondrial membrane has a much larger effect than the membrane potential on the total proton-motive force. 14-15 Some bacteria can live both aerobically and anaerobically. How does the ATP synthase in the plasma membrane of th [Show More]

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