Cell Exam II - Cellular and Molecular Biology Exam 2 PDF

Preview

Summary

Cellular and Molecular Biology Exam 2...

Description

Cell Exam II 1. Which of the following is NOT true of the plasma membrane? a. It is composed of an extracellular and intracellular layer of phospholipids b. The extracellular and intracellular layers or leaflets are highly symmetrical c. The membrane contains peripheral proteins d. Integral proteins span through the membrane e. The membrane contains glycolipids and glycoproteins 2. Placing celery sticks in fresh water will make them more turgid and harder. This is because a. The celery is hypotonic to fresh water b. The celery is hypertonic to fresh water c. The celery is isotonic to fresh water d. Water moves from the celery sticks into fresh water e. None of the choices are correct 3. Which of the following statements about the plasma membrane Na+/K+-ATPase pump is INCORRECT? a. Three sodium ions bind to the cytoplasmic side of the protein b. Three sodium ions are translocated out of the cell c. Phosphate facilitates potassium ion binding to the protein d. Two potassium ions are transported into the cell 4. As a scientist you perform an experiment in which you create an artificial cell with a selectively permeable membrane trough which only water can pass. You put a 5M solution of glucose into the cell and you place that into a baker of 10M glucose. What observations do you expect to see? a. Water moves out of the cell b. Glucose moves out of the cell c. No net change in cell weight d. Water moves into the cell e. Glucose moves into the cell 5. The statements about transport of Ca2+ from the cytosol (low Ca2+ concentration) into the endoplasmic reticulum (high Ca2+ concentration) are true EXCEPT which of the following? a. Calcium movement involves the use of a pump b. Calcium movement involves active transport c. Calcium movement occurs by facilitated diffusion using a transporter protein d. Calcium movement requires energy e. Calcium movement occurs through a transmembrane protein

6. Which of the following best describes the selective uptake of a specific cargo molecule into the cell thorough receptor binding and aggregation? a. Pinocytosis b. Receptor-mediated endocytosis c. Autophagocytosis d. Phagocytosis e. Receptor-mediated exocytosis 7. Which of the following can easily diffuse through a lipid bilayer? a. Sodium ions b. Amino acids c. Glucose d. Oxygen e. DNA 8. The selectively permeable characteristic of cell membranes is mainly due to the presence of a. Phospholipids b. Transport proteins c. Glycolipids on the outer surface of the membrane d. Concentration gradients across the membrane e. Cholesterol 9. Which one of the following techniques most accurately describes the method used to study the interior of a biomembrane? a. Transmission electron microscopy b. Fluorescence microscopy c. Freeze-fracture electron microscopy d. Scanning electron microscopy 10. Which of the following is an example of antiport? a. Simultaneous movement of an amino acid and protons into the cell b. Simultaneous movement of an amino acid and protons out of the cell c. Coupling of the inward movement of Na+ with the outward movement of Ca++ d. None of the above 11. A transmembrane channel that opens and closes in response to changes in membrane tension across the membrane would most accurately be referred to as a(n): a. Mechanosensitive channel b. Aquaporin c. Voltage-gated channel d. Ligand-gated channel 12. Unlike primary active transport, secondary active transport does not require an ATP molecule to function a. True b. False

13. Which of the following is the most direct source of energy for cotransport? a. The movement of one of the transported substances up its concentration gradient b. The movement of one of the transported substances down its concentration gradient c. ATP hydrolysis d. ATP formation 14. Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell a. True b. False 15. Which of the following types of solutions cause blood cell lysis (bursting)? a. Hypoosmotic b. Isosmotic c. Hyperosmotic 16. An atom gains energy when a. An electron is lost from it b. It undergoes oxidation c. It undergoes reduction d. It undergoes an oxidation-reduction reaction 17. In a chemical reaction, if G is negative, it means that a. The products contain more free energy than the reactants b. An input of energy is required to break the bonds c. The reaction will proceed spontaneously d. The reaction is endergonic 18. How is ATP used in the cell to produce cellular energy? a. ATP provides energy to drive exergonic reactions b. ATP hydrolysis is coupled to endergonic reactions c. A liberated phosphate group attaches to another molecule, which generates energy d. ATP generates energy by the repulsion of the negatively-charged phosphates 19. Under standard conditions, ATP can release for every molecule a. Less than 1 cal of energy b. 1 to 2 cal of energy c. 7.3 Kcal of energy d. 7.3 cal of energy e. Different amounts of energy depending on the cell

20. One of the most important coenzymes that accepts electrons/hydrogen is a. NAD+ b. NADH c. ATP d. NADPH e. Ribozyme 21. The regulation of glycolytic pathway by ATP binding to the allosteric site of the phosphofructokinase is called a. Competitive inhibition b. Biochemical regulation c. Cellular control d. Product catalysis e. Feedback inhibition 22. The inorganic components that aid in enzyme functioning are called a. Reactants b. Cofactors c. Coenzymes d. Substrates e. Products 23. When the substrate is bound to the enzyme, the shape of the enzyme may change slightly, leading to a. A better induced fit b. A great range of possible catalytic activities c. A greater supply of activation energy d. More permanent binding through intimate total contact e. More possible products of the reaction 24. Match the type of energy on the left with the appropriate description on the right i. Potential energy a. Energy contained with covalent bonds ii. Chemical energy b. Energy associated with movement iii. Kinetic energy c. Energy due to structure or location a. b. c. d. e.

i=c; ii=b; iii=a i=a; ii=c; iii=b i=a; ii=b; iii=c i=b; ii=a; iii=c i=c; ii=a; iii=b

25. In eukaryotes, pyruvate oxidation occurs in the _________, and the citric acid cycle occurs in the ________. a. Cytoplasm; mitochondrial matrix b. Mitochondrial matrix; mitochondrial matrix c. Outer mitochondrial membrane; inner mitochondrial membrane d. Cytoplasm; cytoplasm e. Outer mitochondrial membrane; mitochondrial matrix 26. How does a freshwater organism like an amoeba maintain proper osmotic balance? a. Amoebae have a rigid cell wall which prevents water loss b. The cell membrane of amoebae contains special water pumps to move water into the cytoplasm. c. The cell membrane of amoebae contains special water pumps to move water out of the cytoplasm. d. Amoebae have contractile vacuoles which accumulate water, fuse with the plasma membrane, and discharge the water into the extracellular environment e. No special mechanism is necessary because the cytoplasm is isotonic with the extracellular environment. 27. As energy is being reconverted through the many forms, it is continuously lost as a. Electricity b. Light c. Sound d. Heat e. Chemical energy 28. During glycolysis, ATP is primarily produced by a. Oxidative phosphorylation b. Substrate-level phosphorylation c. Redox reactions d. All of the above 29. Which one of the following components of the electron transport chain does not actively pump protons across the inner mitochondrial membrane? a. NADH dehydrogenase b. Succinate reductase c. Cytochrome b-c1 d. Cytochrome oxidase 30. In eukaryotes, the glycolytic reactions take place in the a. Mitochondria of the cell b. Cytoplasm of the cell c. Ribosomes of the cell d. Endoplasmic reticulum of the cells e. Golgi bodies of the cell 31. In oxidative respiration, energy is harvested from glucose molecules in a sequence of four major pathways. Which of the following is not one of these four pathways?

a. b. c. d. e.

Krebs cycle Glycolysis Electron transfer through the transport chain Beta oxidation Pyruvate oxidation

32. In the glycolytic pathway, how many ATP molecules are USED by one glucose molecule? a. 1 b. 2 c. 3 d. 4 33. When ATP levels are high, acetyl-CoA is channeled into a. Fermentation b. Fatty acid biosynthesis c. Protein synthesis d. Nucleic acid synthesis 34. A single glucose molecule can drive the Krebs cycle a. One turn b. Two turns c. Three turns d. Four turns e. Six turns 35. The coenzyme electron carriers produced in the Krebs cycle are a. ATP and ADP b. Pyruvate and acetyl-CoA c. FADH2 and NADH d. NAD and NADH e. NADH and ATP 36. Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always a. ADP b. ATP c. NAD+ d. Pyruvate e. Alcohol 37. Select the correct sequence concerning glucose metabolism. a. Glycolysis – Pyruvate – Acetyl CoA – Electron Transport Chain – Krebs b. Glycolysis – Pyruvate – Acetyl CoA – Krebs – Electron Transport Chain c. Glycolysis – Acetyl CoA – Pyruvate – Electron Transport Chain – Krebs d. Glycolysis – Acetyl CoA – Pyruvate – Krebs – Electron Transport Chain

38. There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered. Select the correct order from the following choices. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD). a. Acetyl-CoA joins the Krebs cycle and unites with oxaloacetate – Forming citrate – Which forms beta-ketoglutarate – Which forms succinyl CoA –Which forms Succinate – Which forms fumarate – Which forms malate – Which forms oxaloacetate b. Acetyl-CoA joins the Krebs cycle and unites with oxaloacetate – Forming citrate – Which forms alpha-ketoglutarate – Which forms succinyl CoA –Which forms Succinate – Which forms malate – Which forms fumarate – Which forms oxaloacetate c. Acetyl-CoA joins the Krebs cycle and unites with oxaloacetate – Which forms alpha-ketoglutarate – Forming citrate - Which forms succinyl CoA –Which forms Succinate –Which forms fumarate – Which forms malate – Which forms oxaloacetate d. Acetyl-CoA joins the Krebs cycle and unites with oxaloacetate – Forming citrate – Which forms alpha-ketoglutarate – Which forms succinyl CoA – Which forms Succinate – Which forms fumarate – Which forms malate – Which forms oxaloacetate 39. Pyruvate dehydrogenase is a multienzyme complex that catalyzes a series of reactions. Which of the following is NOT carried out by pyruvate dehydrogenase? a. A decarboxylation reaction b. The production of ATP c. Producing an acetyl group from pyruvate d. Combining the acetyl group with a coenzyme 40. How many molecules of CO2 are produced for each molecule of PYRUVATE that passes through glycolysis and the Krebs cycle? a. 2 b. 3 c. 6 d. 7 41. One molecule of glucose produces a net of __ ATP and ____ NADH by glycolysis, ____ NADH by pyruvate oxidation, and ____ ATP, ____ NADH, and _____ FADH 2 by Krebs cycle. a. 2, 2, 1, 1, 3, 1 b. 4, 2, 2, 2, 6, 2 c. 2, 2, 2, 1, 3, 1 d. 2, 2, 2, 2, 6, 2 42. Oxygen acts as a. A carrier of electrons, passing electrons down the chain b. A reducing agent c. The terminal electron acceptor d. A coenzyme

43. In how many of the biochemical reactions of the tricarboxylic acid cycle is NADH formed? a. NADH is formed in two reactions b. NADH is formed in eight reactions c. NADH is formed in three reactions d. NADH is formed in one reaction only 44. How is oxygen consumption related to the synthesis of ATP by ATP synthase? a. Oxygen is consumed during the citric acid cycle b. Oxygen is consumed in order to sustain glycolysis c. Oxygen is necessary to maintain the proton gradient that drives ATP synthesis by ATP synthase d. Oxygen binds ATP synthase to activate the enzyme 45. The spinning of the ___ subunit of ATP synthase results in the change in conformation of ___ subunits resulting in ATP synthesis. a. ,  b. ,  c. ,  d. ,  46. In glycolysis the three steps in which energy is given out are a. G3P  1,3BPG  3PG and PEP  Pyruvate b. G3P  3PG, 2PG  PEP and PEP  Pyruvate c. 3PG  2PG  PEP and PEP  Pyruvate 47. In the following order of reactions CO2 is removed and NAD+ is reduced to NADH in the Krebs cycle. a. Isocitrate  Alpha-ketoglutarate  Succinyl CoA b. Succinate  Fumarate  Malate  Oxaloacetate c. Citrate  Alpha-ketoglutarate  Succinyl CoA d. Oxaloacetate  Alpha-ketoglutarate  Succinate 48. Each NADH passes the electrons to ____ protons pumps while each FADH 2 passes the electrons to ____ proton pumps in the electron transport chain. a. 2,2 b. 3,3 c. 3,2 d. 1,3 49. Secondary metabolism produces one of the following products: a. Glucose b. ATP c. Streptomycin d. Amino acids

50. The water necessary for photosynthesis a. Is split into H2 and O2 b. Is directly involved in the synthesis of carbohydrate c. Provides the electrons to replace lost electrons in photosystem II d. Provides H+ needed to synthesize G3P e. None of the above 51. What are the physiological effects of an accumulation of lactic acid? a. Lactic acid increases the heart rate b. Lactic acid allows a more efficient use of ATP c. Lactic acid increases the breathing rate d. Lactic acid causes muscles to burn and can cause cramping 52. Flattened sacs of internal membranes which have proteins embedded and are associated with photosynthesis are called a. Chloroplasts b. The photosystems c. Thylakoid d. Stroma e. Cristae 53. The reaction center pigment differs from the other pigment molecules of the lightharvesting complex in that a. The reaction center pigment is a carotenoid b. The reaction center pigment absorbs light energy and transfers that energy to other molecules without the transfer of electrons c. The reaction center pigment transfers excited electrons to other molecules d. The other pigments transfer high-energy electrons to other pigment molecules e. The reaction center acts as an ATP synthase to produce ATP 54. Organisms which synthesize organic molecules from inorganic sources are most accurately referred to as ____, while organisms which must consume organic molecules from their environments to survive are most accurately referred to as ____. a. Heterotrophs; photoautotrophs b. Plants; animals c. Photoautotrophs, chemoautotrophs d. Autotrophs; Heterotrophs e. Auxotrophs; autotrophs 55. When an electron absorbs energy and exists in an excited state, the electron can: a. Drop back down to its original energy level and release light b. Be removed from one molecule and transferred to a different molecule c. Drop back down to its original energy level and release heat d. A and B e. A, B, and C

56. Calvin cycle reactions occur in the _____, while light reactions occur in the _____. a. Thylakoid lumen; Thylakoid membranes b. Stroma; Thylakoid membranes c. Stroma; Thylakoid lumen d. Intermembrane space; Stroma 57. The primary electron acceptor in Photosystem II is: a. QA b. D1 c. CP43 d. Pheophytin e. P680 58. _____ is the primary function of photosystem I in photosynthesis and _______ is the primary function of photosystem II in photosynthesis. a. Production of oxygen; production of glucose b. Production of glucose; production of oxygen c. Synthesis of NADH; production of oxygen and ATP d. Synthesis of ATP; synthesis of NADH e. Synthesis of NADPH; synthesis of ATP and production of oxygen 59. Which of the following is common to both cellular respiration and the light reactions of photosynthesis? a. The transfer of electrons to glucose b. The chemiosmotic formation of ATP c. Oxygen is one of the byproducts d. Mitochondria are essential organelles 60. _____ clusters are responsible for splitting water in the thylakoid lumen. a. Calcium b. Iron c. Manganese d. None of the above

1. B 2. B 3. C 4. A 5. C 6. B 7. D 8. B 9. C 10. C 11. A 12. A 13. B 14. B 15. A 16. C 17. C 18. B 19. C 20. A 21. E 22. B 23. A 24. E 25. B 26. D 27. D 28. B 29. B 30. B

31. D

32. B 33. B 34. B 35. C 36. C 37. B 38. D 39. B 40. B 41. D 42. C 43. C 44. C 45. D 46. A 47. A 48. C 49. C 50. C 51. D 52. C 53. C 54. D 55. E 56. B 57. D 58. E 59. B 60. C...