front 1 An organism is discovered that thrives in both the presence and absence of oxygen. Interestingly, as oxygen is removed from the organism's environment, the rate of sugar consumption increases while the growth rate decreases. What do these observations suggest about the likely identity of this organism? | back 1 It is a facultative anaerobic organism. |
front 2 Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation? | back 2 oxidation of NADH to NAD+ |
front 3 In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules? | back 3 ATP, CO2, and ethanol (ethyl alcohol) |
front 4 Which of the following metabolic processes take place in the cytosol of a eukaryotic cell? | back 4 glycolysis and fermentation |
front 5 Which of the following metabolic processes normally occurs regardless of whether or not oxygen (O2) is present? | back 5 glycolysis |
front 6 What kinds of cells carry out ATP synthesis by chemiosmosis? | back 6 all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors |
front 7 Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." The little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. Which of the following statements about these inside-out membrane vesicles is true? | back 7 The inside of the vesicles will become acidic when NADH is added. |
front 8 Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." The little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. After the disruption, which components involved in oxidative phosphorylation must be present for electron transfer and ATP synthesis to still occur? | back 8 all of the electron transport system and ATP synthase |
front 9 A person on a strict diet and exercise regimen lost 7 kg (about 15 pounds) of body fat in just two weeks. What is the most likely way that the lost fat left the body? | back 9 It was released as CO2 and H2O. |
front 10 In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve? | back 10 It increases the surface for oxidative phosphorylation. |
front 11 If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water? | back 11 12.5 |
front 12 The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes? | back 12 coupling of an endergonic reaction to an exergonic reaction |
front 13 Approximately how many molecules of ATP are produced from the complete oxidation of one molecule of glucose (C6H12O6) in aerobic cellular respiration? | back 13 30-32 |
front 14 Which of the following processes generates a proton-motive force in mitochondria? | back 14 pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space |
front 15 Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells? | back 15 mitochondrial intermembrane space |
front 16 In chemiosmosis, what is the most direct source of energy that is used to convert ADP + i to ATP? | back 16 energy released from movement of protons through ATP synthase, down their electrochemical gradient |
front 17 Water is one of the end products of aerobic respiration. What is the source of the oxygen atom used in formation of the water? | back 17 molecular oxygen (O2) |
front 18 Which of the following statements best describes the primary role played by oxygen in cellular respiration? | back 18 It serves as the final acceptor for electrons from the electron transport chain. |
front 19 During aerobic respiration, which of the following molecules directly donates electrons to the electron transport chain at the lowest energy level? | back 19 FADH2 |
front 20 Where are the proteins of the electron transport chain located? | back 20 mitochondrial inner membrane |
front 21 Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration? | back 21 glucose → NADH → electron transport chain → oxygen |
front 22 Which of the following processes is driven by chemiosmosis? | back 22 oxidative phosphorylation |
front 23 Which of the following statements about the electron transport chain is true? | back 23 It consists of a series of redox reactions |
front 24 Which of the following events takes place in the electron transport chain? | back 24 the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle |
front 25 Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate? | back 25 acetyl CoA |
front 26 In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO2, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. Which of the following sets of products result from these reactions? | back 26 acetyl CoA, NADH, and CO2 |
front 27 Use the following information to answer the question below. | back 27 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 |
front 28 Use the following information to answer the question below. | back 28 Oxaloacetate will accumulate and citric acid will decrease. |
front 29 Use the following information to answer the question below. | back 29 4 |
front 30 If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in oxidation of pyruvate to acetyl CoA? | back 30 1/3 |
front 31 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? | back 31 oxidation of pyruvate to acetyl CoA and the citric acid cycle |
front 32 Use the following information to answer the question below. | back 32 The rates of ATP production and carbon dioxide production would both increase. |
front 33 Which electron carrier(s) function in the citric acid cycle? | back 33 NADH and FADH2 |
front 34 Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules? | back 34 NADH |
front 35 During which of the following metabolic processes is most of the CO2 from the catabolism of glucose is released? | back 35 the citric acid cycle |
front 36 Which kind of metabolic poison would most directly interfere with glycolysis? | back 36 an agent that closely mimics the structure of glucose but is not metabolized |
front 37 In glycolysis, for each molecule of glucose oxidized to pyruvate, ________. | back 37 two molecules of ATP are used, and four molecules of ATP are produced |
front 38 Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products? | back 38 2 NADH, 2 pyruvate, and 2 ATP |
front 39 The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol, and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed? | back 39 Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. |
front 40 Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis? | back 40 100% |
front 41 A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply? | back 41 Catabolic processes are activated that generate more ATP. |
front 42 Why are carbohydrates and fats frequently considered high-energy foods? | back 42 They contain many electrons associated with hydrogen atoms. |
front 43 The oxygen consumed during cellular respiration is directly involved in which of the following processes or events? | back 43 accepting electrons at the end of the electron transport chain |
front 44 Which of the following statements about NAD+ is true? | back 44 NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. |
front 45 When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes ________. | back 45 reduced |
front 46 What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction? | back 46 The glucose molecule is oxidized. |
front 47 Which of the summary statements below describes the results of the following reaction? | back 47 C6H12O6 is oxidized and O2 is reduced. |
front 48 What happens when electrons are passed from one atom to a more electronegative atom? | back 48 The more electronegative atom is reduced, and energy is released. |
front 49 Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction? | back 49 It loses electrons and loses potential energy. |
front 50 In which reactions of cellular respiration and fermentation does substrate-level phosphorylation occur? | back 50 in both glycolysis and the citric acid cycle |