Download 1 1) What kinds of molecules pass through a cell membrane most

Bio 201 Fall 2005 Sample Questions: Exam 2
NOTE: These are tough multiple choice questions!! Probably tougher than what you will see on the exam.
If you feel comfortable with these questions, you are in super-great shape. If you would like to work on
easier questions first, check the CD-ROM from the text book. The Chapter Quizzes are easier than this set
of questions, and are a great place to start your studying.
Hope this helps, and feel free to email me with questions. (Answers are at the end).
1) What kinds of molecules pass through a cell membrane most easily?
A) large and hydrophobic
B) small and hydrophobic
C) large polar
D) ionic
E) disaccharides such as sucrose
2) Which of the following would likely move through the lipid bilayer of a plasma
membrane most rapidly?
A) CO2 B) an amino acid C) glucose D) Na+ E) starch
3) Water passes quickly through cell membranes because
A) the bilayer is hydrophilic.
B) it moves through hydrophobic channels.
C) water movement is tied to ATP hydrolysis.
D) it is a small, polar, charged molecule.
E) it moves through aquaporins (water channels) in the membrane.
4) Celery stalks that are immersed in fresh water for several hours become stiff and hard.
Similar stalks left in a salt solution become limp and soft. From this we can deduce that
the cells of the celery stalks are
A) hypotonic to both fresh water and the salt solution.
B) hypertonic to both fresh water and the salt solution.
C) hypertonic to fresh water but hypotonic to the salt solution.
D) hypotonic to fresh water but hypertonic to the salt solution.
E) isotonic with fresh water but hypotonic to the salt solution.
5) You are working on a team that is designing a new drug. In order for this drug to
work, it must enter the cytoplasm of specific target cells. Which of the following would
not be a factor that determines whether the molecule enters the cell?
A) size of the drug molecule
B) charge on the drug molecule
C) similarity of the drug molecule to other molecules transported by the target cells
D) carbohydrate composition of the target cells' plasma membrane
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6) The movement of a substance across a biological membrane against its concentration
gradient with the help of energy input is
A) diffusion.
B) active transport.
C) osmosis.
D) facilitated diffusion.
7) The main difference(s) between facilitated diffusion and active transport is (are)
A) facilitated diffusion moves substances down their concentration gradient and active
transport moves them against their gradient.
B) facilitated diffusion does not rely on cellular energy and active transport does.
C) there are no difference between facilitated diffusion and active transport
D) All of the above
E) A and B
8) White blood cells engulf bacteria through what process?
A) exocytosis
B) phagocytosis
C) pinocytosis
D) osmosis
E) receptor-mediated exocytosis
9) Which of the following statements regarding ATP is (are) correct?
A) ATP serves as the main energy molecule inside cells.
B) ATP drives non-spontaneous reactions in the cell by transferring a phosphate group to
specific reactants.
C) The regeneration of ATP from ADP and phosphate requires energy.
D) A and B only
E) A, B, and C
10) Which of the following forms of energy is least available to accomplish cellular
work?
A) light energy
B) electrical energy
C) heat energy
D) mechanical energy
E) potential energy
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11) Which of the following statements regarding enzymes is true?
A) Enzymes are nucleic acids
B) Enzymes increase the rate of a reaction.
C) Enzymes typically have a wide variety of substrates.
D) Enzymes are permanently altered by the reactions they catalyze.
12) Which of these statements regarding enzymes is false?
A) Enzymes are proteins that function as catalysts.
B) Enzymes display specificity for certain molecules with which they interact.
C) Enzymes raise the activation energy for the reactions they catalyze.
D) An enzyme may be used many times over for a specific reaction.
13) Which of the following statements is (are) correct about an oxidation-reduction (or
redox) reaction?
A) The molecule that is reduced gains electrons.
B) The molecule that is oxidized loses electrons.
C) The molecule that is reduced loses electrons.
D) The molecule that is oxidized gains electrons.
E) Both A and B are correct.
F) Both C and D are correct.
14) Which statement is not correct with regard to redox (oxidation-reduction) reactions?
A) A molecule is reduced if it loses electrons.
B) A molecule is oxidized if it loses electrons.
C) An electron donor is called a reducing agent.
D) An electron acceptor is called an oxidizing agent.
E) Oxidation and reduction always go together.
15) When electrons move closer to a more electronegative atom, what happens?
A) Energy is released.
B) Energy is consumed.
C) The more electronegative atom is reduced.
D) The more electronegative atom is oxidized.
E) A and C are correct.
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16) Which of the following statements describes the results of this reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
A) C6H12O6 is reduced.
B) O2is oxidized and H2O is reduced.
C) CO2 is reduced and O2 is oxidized.
D) C6H12O6 is reduced and CO2 is oxidized.
E) O2 is reduced and CO2 is oxidized.
17) Which process in eukaryotic cells will proceed normally whether oxygen O2 is
present or absent?
A) electron transport
B) glycolysis
18) 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 cytosol 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.
19) In addition to ATP, what are the end products of glycolysis?
A) CO2 and H2O
B) CO2 and pyruvate
C) NADH and pyruvate
D) CO2and NADH
E) H2O, FADH2, and glucose
20) A molecule that is phosphorylated
A) has an increased chemical reactivity; it is primed to do cellular work.
B) has a decreased chemical reactivity; it is less likely to provide energy for cellular
work.
C) has been oxidized as a result of a redox reaction involving the gain of an inorganic
phosphate.
D) has been reduced as a result of a redox reaction involving the loss of an inorganic
phosphate.
E) has less energy than before its phosphorylation and therefore less energy for cellular
work.
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21) All of the following are functions of the Kreb’s cycle except
A) production of ATP.
B) production of NADH.
C) production of FADH2
D) release of carbon dioxide.
E) adding electrons and protons to oxygen, forming water.
22) Where are the proteins of the electron transport chain located?
A) cytosol
B) mitochondrial outer membrane
C) mitochondrial inner membrane
D) mitochondrial intermembrane space
E) mitochondrial matrix
23) The primary role of oxygen in cellular respiration is to
A) yield energy in the form of ATP as it is passed down the respiratory chain.
B) act as an acceptor for electrons and hydrogen, forming water.
C) combine with carbon, forming CO2.
D) combine with lactate, forming pyruvate.
E) catalyze the reactions of glycolysis.
24) The direct energy source that drives ATP synthesis during respiratory oxidative
phosphorylation is
A) oxidation of glucose to CO2 and water.
B) the flow of electrons from NADH to the mitochondrial electron transport carriers.
C) the difference in H+ concentrations on opposite sides of the inner mitochondrial
membrane.
D) the transfer of phosphate from glycolysis and the Kreb’s cycle intermediate molecules
of ADP.
25) Which of the following normally occurs whether or not oxygen O2 is present?
A) glycolysis
B) fermentation
C) oxidation of pyruvate
D) Kreb’s cycle
E) ATP synthase generating ATP from ADP and phosphate
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26) Molecules that can potentially be converted to intermediates of glycolysis and/or the
Kreb’s cycle include
A) amino acids and proteins.
B) glycerol and fatty acids.
C) glucose and sucrose.
D) starch and glycogen.
E) all of the above
27) A plant cell placed in a hypotonic solution will not lyse because
A) the cell wall prevents the plant cell from bursting.
B) plant plasma membranes are impermeable to water.
C) it shrivels.
D) it becomes turgid.
E) it is flaccid.
28) If the volume of a cell increases when it is placed in a solution, that solution is said to
be __________ to the cell.
A) salty
B) isotonic
C) hypotonic
D) hypertonic
29) The energy given up by electrons as they move through the electron transport chain is
used to _____
A) make NADH
B) manufacture glucose
C) oxidize water
D) pump H+ through a membrane
E) break down glucose
30) The ATP synthase in a human cell gets energy for making ATP directly from _____.
A) sunlight
B) the movement of electrons through a series of carriers
C) the flow of H+ through a membrane
D) the oxidation of glucose
E) the reduction of oxygen
31) Which of the following solutions has the greatest concentration of hydrogen ions
(H+) ?
A) lemon juice at pH 2
B) vinegar at pH 3
C) tomato juice at pH 4
D) urine at pH 6
E) seawater at pH 8
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ANSWERS:
1) B
2) A
3) E
4) C
5) D
6) B
7) E
8) B
9) E
10) C
11) B
12) C
13) E
14) A
15) E
16) A
17) B
18) D
19) C
20) A
21) E
22) C
23) B
24) C
25) A
26) E
27) A
28) C
29)D
30) C
31) C
32) A
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