Download Biology-1 Exam Two You can write on this exam. Please put a W at

Biology-1
Exam Two
You can write on this exam. Please put a W at the top of this page if you choose to. There are a total of 65 questions and one
short answer. Good Luck!
Multiple Choice Questions. Choose the letter that best answers or completes the sentence. (2 pts. each)
1.
Plasma membranes are selectively permeable. This means that,
a. anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy
b. the plasma membrane allows some substances to enter or leave a cell more easily than others
c. glucose cannot enter the cell
d. plasma membranes must be very thick
e. none of the above
2.
Oxygen crosses a plasma membrane by,
a. osmosis
b. active transport
c. passive transport
d. pinocytosis
e. exocytosis
3.
Osmosis can be defined as
a. the diffusion of water
b. the diffusion of nonpolar molecules
c. active transport
d. the diffusion of a solute
e. none of the above
4.
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and
osmosis is allowed to take place, the water will
a. exhibit a net movement to the side with lower water concentration
b. exhibit a net movement to the side with higher water concentration
c. exhibit a net movement to the side with lower solute concentration
d. exhibit an equal movement in both directions across the membrane
e. none of the above
5.
In the lab, you use a special balloon that is permeable to water, but not sucrose, to make an "artificial cell." The balloon is filled
with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water.
Which of the following will occur?
a. water will leave the balloon
b. water will enter the balloon
c. sucrose will leave the balloon
d. sucrose will enter the balloon
e. no net change in the volume of the balloon
6.
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The
presence of these organelles tells you that the environment
a. is isotonic to the protozoan
b. is hypotonic to the protozoan
c. contains a higher concentration of solutes than the protozoan
d. is hypertonic to the protozoan
e. is none of the above
7.
If placed in distilled water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?
a. the expulsion of water by the plant cell's central vacuole
b. the relative impermeability of the plant cell wall to water
c. the fact that plant cells are isotonic to distilled water
d. the relative inelasticity and strength of the plant cell wall
e. none of the above
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Exam Two
8. Which one of the following types of molecules can pass directly through the plasma membrane without the help of a
carrier/channel protein?
a. a small, hydrophobic molecule
b. a large protein
c. a disaccharide like lactose
d. a and b only
e. none of the above
9.
Passive membrane transport processes include______________.
a. movement of a substance down its concentration gradient
b. movement of water from an area of low concentration to an area of high concentration
c. consumption of ATP
d. the use of transport proteins when moving substances from areas of low to high concentration
e. none of the above
10. Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration
gradient.
a. energy and transport proteins . . . down
b. transport proteins . . . down
c. energy and transport proteins . . . against
d. transport proteins . . . against
e. enzymes and energy…against
11. The process of a white blood cell engulfing a bacterium is
a. osmosis
b. receptor-mediated endocytosis
c. pinocytosis
d. phagocytosis
e. exocytosis
12. How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive
inhibitor?
a. Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants.
b. Competitive inhibitors change the enzyme's structure; noncompetitive inhibitors cause polypeptide subunits to dissociate
(break apart).
c. Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to an allosteric (different)
site on the enzyme.
d. None of the above.
13. Which of the following statements about the ATP molecule is true?
a. It contains five phosphate groups.
b. Extremely stable bonds link the second and third phosphate groups.
c. It contains the sugar glucose.
d. It releases energy when one phosphate group leaves ATP.
e. None of the above
14. Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing
a. chemical energy into kinetic energy
b. chemical energy into potential energy
c. kinetic energy into potential energy
d. kinetic energy into thermal energy
e. mechanical energy into chemical energy
15. According to ________, energy cannot be created or destroyed.
a. Aristotle's first principle
b. the first law of thermodynamics
c. the second law of thermodynamics
d. the third law of thermodynamics
e. the law of entropy
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Exam Two
16. Which of the following processes is endergonic?
a. the burning of wood
b. photosynthesis
c. the breakdown of glucose
d. cellular respiration
e. fermentation
17. When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n)
________ reaction.
a. exergonic . . . endergonic
b. endergonic . . . exergonic
c. exergonic . . . spontaneous
d. spontaneous . . . exergonic
e. reduction….oxidation
18. Functions of membrane proteins include,
a. acting as receptors
b. transporting materials across the plasma membrane
c. acting as enzymes
d. a and b only
e. all of the above
19. Which of the following statements about glycolysis false?
a. Glycolysis has steps involving oxidation-reduction reactions.
b. The enzymes of glycolysis are located in the cytoplasm of the cell.
c. Glycolysis can operate in the complete absence of O2.
d. The end products of glycolysis are CO2 and H2O.
e. Glycolysis makes ATP exclusively through substrate-level phosphorylation.
20. Which metabolic pathway uses oxygen as the oxidizing agent?
a. aerobic (cellular) respiration
b. anaerobic respiration
c. photosynthesis
d. glycolysis
e. fermentation
21. What determines whether pyruvate enters into aerobic respiration or a fermentation process?
a. presence of sufficient mitochondria
b. availability of sufficient glucose
c. presence of lactate
d. presence of FAD
e. availability of sufficient oxygen
22. How do cells recycle NADH back to NAD + during alcohol fermentation in yeast cells?
a. by converting pyruvate to lactic acid
b. by converting pyruvate to ethanol and carbon dioxide
c. by converting pyruvate to acetyl CoA
d. by converting glucose to pyruvate
e. none of the above
23.
_________________________ is reduced by NADH in lactic acid fermentation.
a.
Pyruvate
b. Glucose
c. Lactate
d. Acetyl CoA
e. Ethanol
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Exam Two
24. The energy of the electrons passing along the electron transport chain is used to make______.
a. lactic acid
b. citric acid
c. alcohol
d. ATP
e. NADH/NADPH
25. Which of the following is not a product of the Kreb’s cycle?
a.
Acetyl CoA
b. CO2
c. NADH
d.FADH2
e.ATP
26. NAD+ acts as a(n) __________in cellular respiration.
a. reducing agent
b. oxidizing agent
c. electron donor
d. base
e. substrate
27. Redox reactions
a. power the synthesis of ATP in photosynthesis
b. power the synthesis of ATP in cellular respiration
c. involve the transfer of electrons to more electronegative atoms
d. b and c
e. all of the above
28. During aerobic respiration, electrons travel downhill in which sequence?
a. food → citric acid cycle → ATP → NAD+
b. food → NADH → electron transport chain → oxygen
c. glucose → pyruvate → ATP→ oxygen
d. glucose → ATP → electron transport chain → NADH
e. food → glycolysis → citric acid cycle → NADH → ATP
29. How is the oxygen that is breathed in during respiration used in cellular respiration?
a. oxygen is converted into CO2 and breathed out.
b. oxygen is used to produce glucose
c. oxygen is converted into ATP
d. oxygen is the final electron acceptor of the electron transport chain.
e. none of the above
30. 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. These three steps result in the formation of
a. acetyl CoA, O2, and ATP.
b. acetyl CoA, FADH2, and CO2.
c. acetyl CoA, FAD, and CO2.
d. acetyl CoA, NADH, and CO2.
e. acetyl CoA, NAD+, ATP, and CO2.
31. Which of the following is not associated with the electron transport chain in cellular respiration?
a. proteins that alternate between oxidized and reduced states
b. proton ion gradient
c. reduction of oxygen
d. reduction of pyruvate
e. oxidative phosphorylation
32. The citric acid cycle begins as the two carbons of acetate are added to the organic compound __________.
a.
malate
b. citrate
c. fumarate
d. succinate
e.oxaloacetate
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Exam Two
33. In cellular respiration CO2 is first produced during
a. glycolysis
b. the grooming step between glycolysis and Kreb’s cycle
c. the Krebs cycle
d. the electron transport chain
e. none of the above
34. In eukaryotic cells, glycolysis occurs in the _________ and oxidative phosphorylation occurs in the____________.
a. nucleus, mitochondria
b. chloroplast, mitochondria
c. mitochondria, cytoplasm
d. cytoplasm, chloroplasts
e. cytoplasm, mitochondria
35. In oxidative phosphorylation, what is the most direct source of energy that is used to convert ADP + P i to ATP?
a. energy released as electrons flow through the electron transport system
b. energy released from substrate-level phosphorylation
c. energy released from ATP synthase pumping hydrogen ions against their concentration gradient
d. energy released from movement of protons through ATP synthase
e. No external source of energy is required because the reaction is exergonic.
36. When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the
direct result from this is
a. formation of ATP.
b. reduction of NAD+.
c. restoration of the Na+/K+ balance across the membrane.
d. creation of a proton gradient.
e. lowering of pH in the mitochondrial matrix.
37. What is a primary difference between cellular respiration and photosynthesis?
a. Carbohydrates are oxidized by cellular respiration and water is oxidized by photosynthesis.
b. Organic compounds are produced by cellular respiration and consumed in photosynthesis.
c. Cellular respiration uses the electron transport system to form ATP and photosynthesis uses fermentation to form ATP.
d. Cellular respiration reduces carbon dioxide and photosynthesis reduces oxygen.
e. None of the above
38. Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and
water?
a. glycolysis
b. fermentation
c. oxidation of pyruvate to acetyl CoA
d. citric acid cycle
e. oxidative phosphorylation
39. In plants, the ATP synthase molecules are located
a. in the stroma
b. on the thylakoid membrane
c. on the cristae
d. b and c
e. none of the above
40. Pigments are,
a. carbohydrates
b. nucleic acids
c. proteins
d. triglycerides
e. none of the above
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41. What color of light is least effective in driving photosynthesis?
a.
blue
b. green
c. red
Exam Two
d. yellow
e. orange
42. You have just discovered a new flower species that has a unique photosynthetic pigment. The leaves of this plant appear to be
reddish yellow. What wavelengths of visible light are NOT being absorbed by this pigment?
a. Red and yellow
b. Blue and violet
c. Green and yellow
d. Blue, green and red
e. Green, blue and violet
43. Light reactions split a molecule to produce hydrogen gas and oxygen. This molecule is:
a.
water
b. carbon dioxide
c. glucose
d. lactic acid
e. acetate
44. Oxygen is produced during which stage of photosynthesis?
a. Calvin Cycle
b. citric acid cycle
c. light reactions
d. dark reactions
e. glycolysis
45. In mechanism, photophosphorylation is most similar to
a. substrate-level phosphorylation in glycolysis
b. oxidative phosphorylation in cellular respiration
c. the calvin cycle
d. carbon fixation
e. reduction of NADP+
46. For chloroplasts to produce sugar from CO2 in the dark, they would require an artificial supply of ___________ and
_____________.
a.
ADP ; NADP+
b. ADP; NADPH
c.ATP ;NADP+
d. ATP; NADPH
e. ATP; NAD+
47. In plants, ________________ is an enzyme that fixes CO2 in the Calvin cycle.
a.
decarboxylase
b. dehydrogenase
c. rubisco
d. hydrolase
e. none of the above
48. Carbon fixation
a. occurs when carbon atoms from CO2 are incorporated into an organic molecule
b. supplies the cell with ATP
c. occurs during the light reactions
d. provides the cell with a supply of NADPH molecules
e. all of the above
49. What is the name of the organic compound that CO2 first gets attached to in the Calvin cycle?
a. rubisco
b. 3-phosphoglycerate
c. ribulose bisphosphate (RuBP)
d. NADPH
e. glyceraldehydes-3-phosphate (G3P)
50. Photosystem II,
a. functions first in photosynthesis
b. contains a chlorophyll a that best absorbs light at 680 nanometers
c. is located on the thylakoid membrane
d. passes electrons to the electron transport chain
e. all of the above
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Exam Two
51. Photosystem I contains a special chlorophyll a molecule in the reaction center that is best at absorbing wavelengths of _____ nm.
a.
238
b. 300
c. 480
d. 680
e. 700
52. The chloroplast ATP synthase
a. is a nucleic acid complex.
b. transports H+ ions from the stroma to the thylakoid space.
c. couples the flow of H+ to the phosphorylation of NADP+.
d. is embedded in the inner membrane of the chloroplast.
e. helps transport H+ against the concentration gradient.
53. Where does the Calvin cycle occur?
a. thylakoid space
b. thylakoid membrane
c. stroma
d. mitochondrion
e. none of the above
54. Plants that fix CO2 into organic compounds at night when the stomata are open and carry out the Calvin cycle during the day
when the stomata are closed are called,
a.
C3 plants
b. C4 plants
c. CAM plants
d. B and C only
e. A, B, and C
55. Which of the following does not occur during the Calvin cycle?
a. carbon fixation
b. oxidation of NADPH
c. release of oxygen
d. regeneration of the CO2 acceptor
e. consumption of ATP
56. Why is it difficult for most plants to carry out photosynthesis in very hot, dry environments such as deserts?
a. The light is too intense and destroys the pigment molecules.
b. The closing of stomata keeps CO2 from entering and O2 from leaving the plant.
c. They must rely on photorespiration to make ATP.
d. CO2 builds up in the leaves, blocking carbon fixation.
e. None of the above
True/False Questions. If any portion of the statement is false, the entire statement is false. (1pt. each)
A = True B= False
57. The transfer of a phosphate group to another molecule or compound is called phosphorylation. (T/F)
58. When an enzyme catalyzes a reaction, it raises the activation energy so that the reaction proceeds faster. (T/F)
59. In photosynthesis, for every 3 molecule of CO2 that enter the Calvin cycle, 1 G3P molecule is produced. (T/F)
60. NADPH acts as an oxidizing agent in photosynthesis. (T/F)
61. Glycolysis is a metabolic pathway shared by both cellular respiration and fermentation. (T/F)
62. Chemiosmosis occurs in photosynthesis but not in cellular respiration. (T/F)
63. The electrons lost from the reaction center of photosystem II are replaced by electrons from H 2O. (T/F)
64. Dehydrogenase enzymes work by removing phosphate groups from certain molecules. (T/F)
65. Photorespiration does not produce sugar or ATP, but consumes oxygen. (T/F)
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Biology-1
Exam Two
Last Name______________________________________________
First Name________________________________
Write your name above and separate this sheet from the rest of the exam packet. Please fold your scantron inside of this
sheet lengthwise and place it in the appropriate folder in the front of the class.
In the space below list and clearly define four similarities between cellular respiration and photosynthesis. This means
that you will provide a clear definition of each similarity that you list. (4 points)
Extra Credit
1. Draw the compounds formed during the steps of the Kreb’s cycle. Next to your diagram discuss the
following: 1) What is the purpose of this overall process? 2) Where are carbons lost from the cycle and
through what process? 3) List how many molecules of ATP are produced in this cycle per glucose molecule
and by what process and 4) List four products of the Kreb’s cycle and what each one will be used for (what
will happen to each product)? (6 points)
OR
2. Draw the compounds formed during the steps of the Calvin cycle. Next to your diagram discuss the
following: 1) What are the three major phases of the Calvin cycle? 2) What is the purpose of this overall
process? 3) Where are carbons gained, through what process, and what enzyme is responsible for this
process? 4) List how many molecules of ATP are consumed and why (how is ATP used)? 5) Name one
specific product of the cycle (abbreviation ok) and what it will be used for. (6 points)
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