Biology Exam 2 Study

10.Some bacteria can use sulfur instead of oxygen as a final electron acceptor. What would they _______ produce during anaerobic respiration? A. H2S B. S2 C. H2O D. O2 E. H2O2

A

11. The ATP made during glycolysis is generated by _______ A. substrate-level phosphorylation. B. electron transport. C. photophosphorylation. D. chemiosmosis. E. oxidation of NADH to NAD+

A

18. Which of the following factors would tend to increase membrane fluidity ______ A. a greater proportion of unsaturated phospholipids B. a greater proportion of saturated phospholipids C. a lower temperature D. a relatively high protein content E. none of these would increase membrane fluidity

A

23. A red blood cell placed in a hypotonic solution will _____ A. take up water, swell, and perhaps burst. B. become impermeable and prevent water loss. C. remain the same size. D. lose water and shrivel up E. none of the choices are correct

A

26. When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? _____ A. The pH of the matrix increases B. ATP synthase pumps protons by active transport C. The electrons gain free energy D. The cytochromes phosphorylate ADP to form ATP E. NAD+ is oxidized

A

29. The free energy (G) of the reactants for a particular reaction is 100 kcal/mol and the _____ free energy (G) of the products is 50 kcal/mol. This reaction is A. exergonic B. endergonic C. at equilibrium D. can't determine what type of reaction this is based on the information provided E. cryogenic

A

34. Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? _____ A. The light reactions provide ATP and NADPH to the Calvin cycle. B. There is no relationship between the light reactions and the Calvin cycle. C. The light reactions provide sugars to the Calvin cycle. D. The light reactions supply the Calvin cycle with CO2. E. The light reactions provide the Calvin cycle with pyruvate.

A

38. Placing celery sticks in water with a high salt concentration makes them wilt. This is because _____ A. the celery is hypotonic to salt water B. the celery is hypertonic to salt water. C. the celery is isotonic to salt water. D. the salt water is hypotonic to the celery E. salt moves from the water into the celery sticks.

A

44. If one were to double the amount of enzyme in a reaction with a ∆G of -5 kcal/mole, what would the ∆G be? _____ A. -5 kcal/mole B. -10 kcal/mole C. -20 kcal/mole D. +5 kcal/mole E. +10 kcal/mole

A

46. A scientist produces an artificial membrane from phospholipids and notices that oxygen, _____ but not glucose readily moves through the membrane. What might account for the inability of glucose to move through the artificial membrane? A. The artificial membrane lacked a protein needed for glucose transport. B. The artificial membrane lacked the appropriate types of phospholipids for glucose transport. C. Oxygen readily passes through the membrane, so glucose should have as well. D. The membrane lacked an adequate amount of amphipathic molecules for glucose transport. E. Thermodynamics does not allow glucose to pass through membranes produced either artificially or from living organisms.

A

47. Water held behind a dam would best reflect _____ A. potential energy B. kinetic energy C. chemical energy D. heat energy E. none of the choices are correct

A

7. The complete oxidation of a mole of glucose releases 686 kcal of energy (∆G = -686 kcal/mol). The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency of cellular respiration for a "mutant" organism that produces only 10 moles of ATP for every mole of glucose oxidized, rather than the usual 36-38 moles of ATP? _______ A. 10% B. 30% C. 60% D. 80% E. 90%

A

12. How is a gradient of H+ ions formed across the inner mitochondrial membrane? _______ A. Electrons move from NADH to a chain of proteins with lower electronegativities. B. The electron transport chain uses energy from the transfer of an electron donated by NADH to pump H+ across the inner mitochondrial membrane against its electrochemical gradient. C. The electron transport chain uses ATP to pump H+ across the inner mitochondria membrane against its electrochemical gradient. D. ATP synthase generates a H+ gradient across the inner mitochondrial membrane. E. The electron transport chain of proteins contains pores that are leaky to H+.

B

14. If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster _______ yield of product is to A. heat the solution to 90°C B. add more of the enzyme C. add more substrate D. add a competitive inhibitor E. add a non-competitive inhibitor

B

17. Your liver produces 90% of the cholesterol found in your body. When cholesterol levels _______ get too high, the first enzyme in the pathway of cholesterol synthesis is inhibited. This is an example of A. A coenzyme B. Feedback inhibition C. Equilibrium D. Denaturation E. Positive feedback

B

19. Which compound has the highest free energy and produces the most ATP when oxidized? _____ A. acetyl CoA B. glucose C. pyruvate D. carbon E. both pyruvate and carbon

B

21. In the biochemical regulation of metabolic pathways, how might one overcome the effects of a competitive inhibitor on enzyme activity? _____ A. Increase the amount of competitive inhibitor. B. Increase the amount of substrate for the enzyme. C. Decrease the temperature of the reaction. D. Decrease the amount of enzyme. E. Add a noncompetitive inhibitor of the enzyme.

B

25. Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _____________ is to ___________________. _____ A. exergonic; spontaneous B. exergonic; endergonic C. free energy; entropy D. work; energy E. entropy; spontaneous

B

27. Which of the following statements is CORRECT about active transport? _____ A. It does not requires energy B. It is an active process in which molecules move from a region of lower concentration to one of higher concentration C. It does not requires integral proteins D. it is an exergonic process E. None of the choices are correct

B

30. The molecule that functions as the reducing agent in a redox or oxidation-reduction reaction. _____ A. neither gains nor loses electrons. B. loses electrons and loses energy. C. gains electrons and loses energy. D. loses electrons and gains energy. E. gains electrons and gains energy.

B

32. Patients with McArdle's Disease lack an enzyme in their livers that catabolizes glycogen. _____ Compared to an unaffected individual, what would you predict about the blood glucose levels of a patient with McArdle's disease? A. Blood glucose levels would be lower because they cannot make glycogen. B. Blood glucose levels would be lower because they cannot break down glycogen. C. Blood glucose levels would be higher because they cannot break down glycogen. D. Blood glucose levels would be higher because they cannot make glycogen. E. Blood glucose levels would be normal, because glycogen is made up of amino acids.

B

35. Certain drugs act as ionophores that cause the mitochondrial inner membrane to _____ be highly permeable to H+. How would such drugs affect oxidative phosphorylation? A. movement of electrons down the electron transport chain would be inhibited B. ATP synthesis would be inhibited C. ATP synthesis would be unaffected D. ATP synthesis would be stimulated E. none of the choices are correct

B

36. Water diffuses through certain organs such as the kidneys and bladder much faster than would _______ occur by passive diffusion through a lipid bilayer alone. What accounts for this more rapid rate of water transport in these organs? A. the composition of lipids changes to promote water transport B. presence of aquaporin channels for facilitated diffusion of water C. presence of a water pump D. presence of an ATP-driven enzyme for water transport E. the presence of molecules that bind water and change its membrane permeability properties

B

41. In mitochondria, exergonic redox reactions _____ A. are the source of energy driving prokaryotic ATP synthesis B. provide the energy that establishes the proton gradient C. reduce carbon atoms to carbon dioxide D. are coupled via phosphorylated intermediates to endergonic processes E. reduce glucose

B

42. Most carbon dioxide from catabolism is released during _____ A. glycolysis B. the citric acid cycle C. lactate fermentation D. electron transport E. oxidative phosphorylation

B

48. The final electron acceptor of the electron transport chain that functions in aerobic oxidative ______ phosphorylation is A. nitrogen B. oxygen C. pyruvate D. glucose E. FAD

B

5. Which of the following is TRUE for endergonic reactions? ______ A. They are considered energetically favorable. B. A net input of energy is required for these reactions to proceed. C. The change in free energy (∆G) is negative. D. The products have less free energy than the reactants. E. Energy is released in the reaction

B

8. A series of enzymes catalyze the reactions A> B >C> D. Substance "D" binds to the enzyme that converts A to B and increases the activity of the enzyme. What is going on here? _______ A. negative feedback B. positive feedback C. feedback inhibition D. receptor-mediated endocytosis E. raising the energy of activation barrier

B

9. A series of enzymes catalyze the reaction X > Y > Z > A. Product A binds to the active site of the enzyme that converts X to Y. This binding decreases the activity of the enzyme. Substance A functions as _______ A. a non-competitive inhibitor B. a competitive inhibitor. C. a substrate D. catalyst E. activator

B

13. Which of the following are produced during the citric acid cycle? _______ A. ATP and NAD+ B. oxygen C. ATP, NADH, and FADH2 D. pyruvate, ATP and NADH E. a proton gradient

C

20. How many net ATP molecules are produced from one molecule of glucose during glycolysis? _____ A. 4 ATP B. 3 ATP C. 2 ATP D. 1 ATP E. 0 ATP

C

22. Where are the electron transport chains located? _____ A. mitochondrial matrix B. mitochondrial outer membrane C. mitochondrial inner membrane D. mitochondrial intermembrane space E. cytosol

C

28. A bowl of sugar water is very stable. However, cells can rapidly break down sugar into _____ carbon dioxide and water. What is the best explanation for this observation? A. Living cells make the water warmer, speeding up the reaction. B. The water is activated by the presence of living cells. C. Enzymes in the cell catalyze the breakdown of glucose. D. Glucose becomes more chemically reactive inside a cell. E. none of the choices are correct

C

37. In the following chemical reaction, NADH is converted to NAD+ + H+. In this reaction _____ NADH has been A. reduced B. phosphorylated C. oxidized D. decarboxylated E. methylated

C

49. Which of the following is NOT true of passive diffusion? _____ A. Passive diffusion is the process by which molecules move from an area of high concentration to an area of low concentration. B. Passive diffusion is a spontaneous process. C. Passive diffusion is a non-spontaneous process. D. Passive diffusion is exergonic. E. Passive diffusion requires no energy.

C

1. The reaction shown in Figure 1 is _____ A. hydrophobic B. hydrophilic C. endergonic D. exergonic E. amphipathic

D

16. After ATP donates a phosphate group in a coupled reaction, it becomes ADP. The ADP can _______ be converted back to ATP in a(an) ________ reaction. A. exergonic B. hydrolysis C. catabolic D. endergonic E. equilibrium

D

2. The energy of activation barrier of the reaction without enzyme is showed in ____ and the energy of activation barrier with enzyme is showed in ____. _____ A. b, d B. d, e C. c, e D. c, b E. c, d

D

3. Energy released by the electron transport chain is used to pump H+ ions into which location ______ A. cytosol B. mitochondrial outer membrane C. mitochondrial inner membrane D. mitochondrial intermembrane space E. mitochondrial matrix

D

31. A series of enzymes catalyze the reaction X > Y > Z > A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of _____ the enzyme. Substance A functions as A. a non-competitive inhibitor B. a competitive inhibitor. C. an allosteric inhibitor. D. A and C E. B and C

D

33. Which portion of the photosynthetic apparatus absorbs light? _____ A. photosystem I B. photosystem II C. NADP reductase D. both photosystem I and photosystem II E. both photosystem I and NADP reductase

D

39. Which of the following statements about metabolism is NOT TRUE? _____ A. Anabolic pathways are endergonic. B. Anabolic pathways "build up" large molecules and consume energy. C. Catabolic pathways "break down" large molecules and release energy. D. Protein synthesis is a catabolic process. E. Catabolic pathways have a free energy change that is less than 0.

D

4. In what way do the membranes of a eukaryotic cell vary? ______ A. they are all identical B. phospholipids are found only in certain membranes C. only certain membranes of the cell are selectively permeable D. certain proteins are unique to each membrane E. only certain membranes are constructed from amphipathic molecules

D

40. What substance produced from the oxidation of glucose in the cytosol gets oxidized more completely in the mitochondria? _____ A. water B. NADH C. NAD+ D. pyruvate E. carbon dioxide

D

43. When electrons held by chlorophyll in photosystem II are boosted to a higher energy level they are captured by ____ A. mitochondria B. calvin cycle C. golgi apparatus D. primary electron acceptor E. ribosomes

D

50. Where does the Calvin cycle occur? _____ A. chloroplast inner membrane B. thylakoid membrane C. thylakoid lumen D. chloroplast stroma E. chloroplast outer membrane

D

6. Which of the following is TRUE for a reaction that has a negative change in free energy (- ∆G) ______ A. The reaction will require energy and is non-spontaneous. B. The reaction will require energy and is spontaneous. C. The reaction will yield energy and is non-spontaneous. D. The reaction will yield energy and is spontaneous E. Not enough information is provided to answer this question

D

15. In photosynthesis, carbon dioxide gas is reduced and combined to form glucose. This is an example of _______ A. exergonic B. catabolism C. spontaneous D. hydrolysis E. anabolism

E

24. Which of the following is FALSE when comparing the mitochondria and chloroplast? _____ A. Both have similar electron transport protein complexes whose structures have been well conserved. B. Both contain ATP synthase. C. Both generate ATP via a H+ electrochemical gradient. D. The intermembrane space of the mitochondria is similar to that of the thylakoid space insofar as each has a higher H+ concentration relative to that of the mitochondrial matrix and chloroplast stroma. E. The stroma of chloroplasts is similar to that of the mitochondrial intermembrane space insofar as each has a higher H+ concentration relative to that of the chloroplast thylakoid lumen and the mitochondrial matrix.

E

45. Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? _____ A. dehydration B. metabolism C. anabolism D. active transport E. catabolism

E