Download 101 -- 2006

BIOL 101 -- Exam 4 – September 13, 2006 – Name: _____________________
Enzymes
__ 1. All the following statements regarding enzymes are true except:
a) Enzymes may require cofactors.
c) Enzymes increase activation energy requirements.
b) Enzymes increase reaction rate.
d) Enzymes are not permanently altered during reaction.
e) All are true.
__ 2. Which is the non-protein, organic component of an enzyme?
a) accessory enzyme
c) coenzyme
e) inducer
b) allosteric enzyme
d) functional group
f) activator
__ 3. End products of biosynthetic pathways often act to block the initial step in that pathway. This
phenomenon is called:
a) allosteric inhibition.
c) irreversible inhibition.
e) end product inducement
b) denaturation.
d) feedback inhibition.
f) flexible feedback.
a. Electrons are removed from on molecule and added to another.
__ 4. Ligases
__ 5.
Isomerases
b. Splits a molecule by the addition of water across its bond.
__ 6.
Hydrolases
c. Hooks two molecules together using the energy from an NTP (e.g. ATP).
__ 7.
Transferases
d. Removes a group forming a double bond or adds a group to a double bond.
__ 8.
Oxidoreductases
e. The molecule keeps the same atoms, but they are rearranged.
__ 9.
Lyases
f. Removes a group from one molecule and add it to another molecule
__ 10. Enzyme inhibitors may bind to the ________ site of an enzyme.
a) allosteric site.
c) affinity site.
e) feedback site
b) inducer site.
d) promoter site.
f) none of these.
__ 11. How does an enzyme catalyze a reaction?
a) by supplying the energy to speed up a reaction
b) by lowering the activation energy of a reaction
c) by lowering the ∆G of a reaction
d) by changing the equilibrium of a spontaneous reaction
e) by increasing the amount of free energy of a reaction
__ 12. Enzymes help the cell make endergonic reactions proceed in the forward direction by:
a) converting these reactions to exergonic reactions.
c) eliminating excess substrate.
b) coupling these reactions to exergonic reactions.
d) binding extraneous inhibitors.
__ 13. A(n) __________is the compound acted on by an enzyme.
a) accessory enzyme b) allosteric group
c) coenzyme
d) substrate
e) activator
__ 14. Enzymes are
a) steroids
c) nucleic acids
e) vitamins
b) proteins
d) complex carbohydrates
__ 15. Tryptophan synthetase is an enzyme that:
a) breaks down tryptophan
c) needs tryptophan as a cofactor
b) makes tryptophan
d) is produced by tryptophan
e) needs tryptophan as a conenzyme
Characteristics of Metabolism
__ 16. Energy is defined as the ability to do work.
a) True
b) False
__ 17. Why is ATP an important molecule in metabolism?
a) It has high energy phosphate bonds.
c) Its hydrolysis is endergonic.
b) Its synthesis is exergonic.
d) It is extremely stable.
e) It is readily obtained from an organism's environment.
__ 18. When NAD is converted to NADH, it was
a) oxidized
b) reduced
c) phosphorylated
d) denatured
e) hydrolyzed
__ 19. Which of the following is an exergonic reaction?
a) break down of glucose
c) synthesis of starch
e) active transport
b) synthesis of glucose
d) movement
__ 20. Which of the following is part of the first law of thermodynamics?
a) Energy cannot be created or destroyed.
c) Energy cannot be transferred or transformed.
b) Kinetic energy is stored energy.
d) Potential energy equals kinetic energy in a reaction.
e) Exergonic reactions are coupled with endergonic reactions.
__ 21. The metabolism of a cell is the sum of all its chemical reactions.
a) True
b) False
__ 22. Which of the following would decrease the entropy within a system?
a) dehydration synthesis
c) respiration
e) catabolism
b) hydrolysis
d) digestion
__ 23. What is the general process of breaking down large molecules into smaller ones called?
a) catalysis
b) metabolism
c) anabolism
d) dehydration
e) catabolism
__ 24. Photosynthesis is an example of an exergonic reaction.
a) True
b) False
__ 25. The most common energy carrier molecule of living organisms is:
a) ATP
c) DNA
e) NADPH
b) Inorganic phosphate
d) Glucose
__ 26. According to the second law of thermodynamics
a) the entropy of the universe is constantly increasing.
b) for every action there is an equal and opposite reaction.
c) every energy transfer requires activation energy from the environment.
d) the total amount of energy in the universe is conserved or constant.
e) energy can be transferred or transformed, but it can be neither created nor destroyed.
__ 27. Which of the following statements is true concerning catabolic pathways?
a) They combine molecules into more complex and energy rich molecules.
b) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
c) They involve endergonic reactions that break complex molecules into simpler ones.
d) They are spontaneous and do not need enzyme catalysis.
e) They build up complex molecules such as protein from simpler compounds.
__ 28. All of the biochemical pathways in a cell constitute
a) coupling reactions.
c) endergonic reactions only.
e) fermentation
b) free energy.
d) exergonic reactions only.
f) metabolism.
__ 29. Coupling occurs when the energy released by an exergonic reaction is
a) used to drive another exergonic reaction.
c) lost as nonusable heat to the environment.
b) used to drive an endergonic reaction.
d) used to decrease the entropy of the universe.
e) All of the choices are correct.
__ 30. The subunits from which ATP is made are
a) ADP and phosphate (Pi).
c) FAD and NADPH.
e) ADP and NAD+.
+
b) FAD and NAD .
d) ADP and FAD.
Glycolysis & Kreb’s TCA Cycle
__ 31. Molecules that can be broken down during cellular respiration include:
a) carbohydrates.
b) proteins.
c) lipids.
d) both carbohydrates and proteins.
e) carbohydrates, proteins, and lipids.
__ 32. The Krebs cycle reduces molecules that then transfer electrons to the electron transport
system. What are these reduced molecules?
a) ATP and CO2
c) FADH2 and NADH
e) NADH, FADH2, and ATP
b) CO2 and FAD
d) NADH and ATP
__ 33. Muscle cells in oxygen deprivation convert pyruvate to _____ and in this step form _____.
a) lactate; ATP
c) alcohol; ATP
e) lactate; NAD
b) alcohol; CO2
d) ATP; NAD
__ 34. Which process in eukaryotic cells will normally proceed whether O2 is present or absent?
a) fermentation
c) Krebs cycle
e) electron transport
b) glycolysis
d) oxidative phosphorylation
__ 35. All of these substances are produced in a muscle cell under anaerobic conditions except:
a) ATP
b) pyruvate
c) lactate
d) Co2
e) NADH
__ 36. At the end of glycolysis, the original carbons of the glucose molecule form:
a) six molecules of carbon dioxide. c) two molecules of pyruvate.
e) two molecules of fructose.
b) two molecules of NADH.
d) two molecules of citric acid.
__ 37. What results if glucose is metabolized under completely anaerobic conditions?
a) Pyruvate immediately enters the Krebs cycle.
b) Pyruvate is converted by fermentation into CO2 and ethanol (yeast) or lactic acid (humans).
c) Pyruvate is converted back to fructose until the concentration of oxygen increases.
d) Pyruvate leaves the cytosol and enters the mitochondrial matrix.
e) Pyruvate is converted to NADH.
__ 38. During glycolysis, what is the net gain of ATP molecules produced?
a) 2
b) 4
c) 34
d) 36
e) 38
__ 39. Where does glycolysis occur?
a) Surface of cell membrane
c) Mitochondrial matrix
e) Nucleus
b) Stroma of chloroplast
d) Cytoplasm
__ 40. Strenuous exercise increases CO2 production. Specifically, where is the CO2 coming from?
a) glycolysis
b) C3 cycle
c) Krebs TCA cycle d) chemiosmosis
e) fermentation
__ 41. Which kind of metabolic poison would interfere with glycolysis?
a) An agent that reacts with oxygen and depletes its concentration in the cell.
b) An agent that binds to pyruvate and inactivates it.
c) An agent that closely mimics the structure of glucose, but is not capable of being metabolized.
d) An agent that reacts with NADH and oxidizes it to NAD+.
e) An agent that inhibits the formation of acetyl coenzyme A.
__ 42. Products of the fermentation process can include
a) carbon dioxide
c) lactic acid
e) none of the above
b) ethanol
d) all of the above
__ 43. The products of the Krebs cycle includes
a) ATP
b) carbon dioxide
c) electron carriers d) b and e only
e) all of the above
__ 44. Electron transport and the Krebs cycle reactions occur in the mitochondria.
a) True
b) False
__ 45. Each turn of the Krebs cycle (including the intermediate reaction) produce ____ CO2.
a) 1
b) 2
c) 3
d) 4
e) 5
Oxidative Phosphorylation
__ 46. Which parts of the mitochondria are directly involved in the synthesis of ATP?
a) matrix
b) inner mitochondrial membrane c) outer mitochondrial membrane
d) a and b
e) a and c
f) a, b and c
__ 47. Where is ATP synthase located in the mitochondrion?
a) ribosomes
c) outer membrane
e) matrix
b) cytochrome system
d) inner membrane
__ 48. Where is the Kreb’s cycle located in the mitochondrion?
a) ribosomes
c) outer membrane
e) matrix
b) cytochrome system
d) inner membrane
__ 49. The electron transport chain results in:
a) the formation of ATP.
c) the formation of a proton gradient.
b) the reduction of NAD.
d) the lowering of pH in the mitochondrial matrix.
e) the restoration of the Na+-K+ balance across the membrane.
__ 50. The primary function of the mitochondrion is the production of ATP. To carry out this
function, the mitochondrion must have all of the following EXCEPT
a) the membrane-bound electron transport chain.
b) proton pumps embedded in the inner membrane.
c) enzymes for glycolysis.
d) enzymes for the Krebs cycle.
e) mitochondrial ATP synthase.
__ 51. The oxygen consumed during cellular respiration is directly involved in
a) glycolysis.
c) the oxidation of pyruvate to acetyl Co A.
b) the citric acid cycle.
d) the phosphorylation of ADP.
e) accepting electrons at the end of the electron transport chain.
__ 52. Compared to FADH2, energy produced from NADH is
a) one-half as much
c) the same
e) twice as much
b) two-thirds as much
d) three-halves more
__ 53. Which of the following is an example of an electron carrier molecule?
a) Citric acid
b) CO2
c) Acetyl CoA
d) NADH
e) ATP
__ 54. The electron transport chain receives electrons directly from:
a) NADH
b) FADH2
c) ATP
d) a and b
e) All of these
__ 55. What is the final electron acceptor in cellular respiration?
a) ATP
b) NADH
c) Carbon dioxide d) Oxygen
e) FADH2
__ 56. During electron transport, ____ accumulate on the outside of the inner mitochondrial
membrane.
a) calcium
b) protons
c) oxygen
d) protons
e) sodium
__ 57. Each NADH produced in the Kreb’s cycle yields ______ molecules of ATP during electron
transport and oxidative phosphorylation.
a) two
b) three
c) tour
d) six
e) either 2 or 3
__ 58. Which of the following is the most electronegative?
a) oxygen
b) water
c) NADH
d) FADH2
e) electron transport chain
__ 59. The enzymes of the electron transport chain are bound to the surface of the cristae. The
cristae are folded inward in order to
a) decrease the intermembrane space.
c) form battery-like "cells" for the electron transport chain.
b) increase diffusion surface for glycolysis.
d) increase surface area for the electron transport chain
e) separate the products from the substrate in the citric acid cycle.
__ 60. Which of the following produces the most electron carriers for the electron transport chain?
a) glycolysis
c) Kreb’s TCA cycle
b) fermentation
d) oxidative phosphorylation
Photosynthesis
__ 61. The cristae of the mitochondria can be compared functionally to the thylakoid membranes
of the chloroplast because both contain a system for:
a) Enzyme synthesis
c) Glucose synthesis
e) Electron transport
b) Pyruvate production
d) Anaerobic respiration
__ 62. Plants need __________ and __________ to perform photosynthesis.
a) oxygen and water
c) carbon dioxide and water
e) none of the above
b) oxygen and carbon dioxide
d) sugar and water
__ 63. From the above picture, “a” represents:
a) oxygen
c) FADH2
e) ATP
g) sugar
i) NADP
b) NADPH
d) water
f) ADP & Pi
h) CO2
j) NAD
__ 64. From the above picture, “b” represents:
a) oxygen
c) FADH2
e) ATP
g) sugar
i) NADP
b) NADPH
d) water
f) ADP & Pi
h) CO2
j) NAD
__ 65. From the above picture, “c” represents:
a) oxygen
c) FADH2
e) ATP
g) sugar
i) NADP
b) NADPH
d) water
f) ADP & Pi
h) CO2
j) NAD
__ 66. From the above picture, “d” represents:
a) oxygen
c) FADH2
e) ATP
g) sugar
i) NADP
b) NADPH
d) water
f) ADP & Pi
h) CO2
j) NAD
__ 67. From the above picture, “g” and “h” represents:
a) oxygen and water
c) FADH and water
e) ADP & Pi
b) NADP and NADPH
d) ATP and NADP
f) sugar and CO2
__ 68. On a global scale, which one(s) of the following are products of photosynthesis and
required for the lives of all aerobically respiring organisms? 1.water, 2. carbon dioxide 3.
oxygen, 4. carbohydrates
a) 1 and 2
b) 2 and 3
c) 3 and 4
d) 1, 2, 3 and 4
__ 69. The color of light least effective in driving photosynthesis is
a) blue.
b) red.
c) orange.
d) green.
e) yellow.
__ 70. Proton gradient for the synthesis of ATP.
a) respiration only
c) both respiration and photosynthesis
b) photosynthesis only
d) neither respiration nor photosynthesis
__ 71. Where do the light-independent reactions of photosynthesis take place?
a) stroma of the chloroplast
b) thylakoid membrane
c) chlorophyll molecule
d) cytoplasm surrounding the chloroplast
e) outer membrane of the chloroplast
__ 72. The pigments excited by sunlight that splits water into oxygen, protons, and electrons are
located in:
a) photosystem I
b) photosystem II
c) the stroma
d) the thylakoid compartment
e) the membrane that forms the thylakoid disk
__ 73. In photosynthesis, the chemical energy formed by the light-dependent reactions is used to
drive the light-independent reactions. The name of the pathway used for the light
independent pathway is
a) Kreb’s cycle
c) photosystem I and II
e) Calvin cycle
b) TCA cycle
d) Harley-Davidson cycle
__ 74. Reduction of CO2.
a) respiration only
c) both respiration and photosynthesis
b) photosynthesis only
d) neither respiration nor photosynthesis
__ 75. Oxidation of water.
a) respiration only
c) both respiration and photosynthesis
b) photosynthesis only
d) neither respiration nor photosynthesis
Scientific Method
__ 76. A good experiment should look at as many variables as possible.
a) True
b) False
__ 77. A hypothesis is much more accepted than a scientific theory.
a) True
b) False
__ 78. A scientific explanation that is tentative and requires more investigation is termed a/an:
a) Theory
b) Fact
c) Control
d) Hypothesis
e) Observation
__ 79. One ml of an experimental drug diluted in a saline solution is injected into 20 pregnant mice
to determine possible side effects. Which of the following is a suitable "control" for this
experiment?
a) 20 male mice injected with 1 ml of saline
b) 20 male mice injected with 1 ml of the drug
c) 20 pregnant mice injected with 2 ml of the drug
d) 20 non-pregnant mice injected with 1 ml of the drug
e) 20 pregnant mice injected with 1 ml of saline
__ 80. What is deductive reasoning?
a) a tentative statement, based on data, that can be used to guide further observations and experiments
b) a report of the findings of scientific experiments
c) a general statement made to infer a specific conclusion, often in "if . . . then" format
d) using isolated facts to reach a general idea that may explain a phenomenon
__ 81. Which statement is not true about a hypothesis?
a) Experiments or observations are undertaken to test a hypothesis.
b) A hypothesis cannot be proven true.
c) A hypothesis cannot be proven false.
d) Data that support a hypothesis do not actually prove it.
e) If data from experiments do not support a hypothesis, the hypothesis must be rejected or revised.
__ 82. In an experiment testing sweetener in the diet of mice, the control group is the one that
has the most sweetener.
a) True
b) False
__ 83. A theory is strongly supported by many forms of evidence, is accepted by an overwhelming
number of scientists, and has not yet been found to be incorrect.
a) True
b) False
__ 84. What type of reasoning is used to make a hypothesis?
a) inductive
b) theoretical
c) cognate
d) deductive
__ 85. What type of reasoning is used to test a hypothesis?
a) inductive
b) theoretical
c) cognate
d) deductive
__ 86. Which statement is false regarding science?
a) Science helps us to understand the natural world
b) Science strives to be objective rather than subjective
c) Correct scientific conclusions are permanent and never subject to change or refinement
d) Information is gathered by scientific methods
e) Information is gained by observing and testing
__ 87. A theory in science is different from the usage of the term in everyday language.
a) True
b) False
__ 88. Which statement is false?
a) Science improved our life by the discovery of antibiotics.
b) Science helps us to understand cancer mechanisms.
c) Science is a basis for all ethical and moral decisions.
d) Science can ease the feeding of the world population by producing new plant strains.
__ 89. The theory of biogenesis states?
a) all organisms contain genes that they pass on to their offspring
b) all life arises from pre-existing life
c) populations change over time, adapting to their environment
d) cells are the smallest unit of life and all organisms are composed of cells
e) all of the above
__ 90. Who is credited as being the first to observe microorganisms?
a) Robert Koch
b) Antonie van Leeuwenhoek
c) Gregory Mendel
d) Alfred Wallace
e) Robert Hooke