Chapter 1 The Foundations of Biochemistry
Multiple Choice Questions
1. Cellular foundations
In a bacterial cell, the DNA is in the:
A) cell envelope.
B) cell membrane.
C) nucleoid.
D) nucleus.
E) ribosomes.
2. Cellular foundations
A major change occurring in the evolution of eukaryotes from prokaryotes was the development of:
A) DNA.
B) photosynthetic capability.
C) plasma membranes.
D) ribosomes.
E) the nucleus.
3. Cellular foundations
In eukaryotes, the nucleus is enclosed by a double membrane called the:
A) cell membrane.
B) nuclear envelope.
C) nucleolus.
D) nucleoplasm.
E) nucleosome.
4. Cellular foundations
The dimensions of living cells are limited, on the lower end by the minimum number of biomolecules
necessary for function, and on the upper end by the rate of diffusion of solutes such as oxygen.
Except for highly elongated cells, they usually have lengths and diameters in the range of:
A) 0.1 m to 10 m.
B) 0.3 m to 30 m.
C) 0.3 m to 100 m.
D) 1 m to 100 m.
E) 1 m to 300 m.
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Which group of single-celled microorganisms has many members found growing in extreme
environments?
A) Bacteria
B) Archaea
C) Eukaryotes
D) Heterotrophs
E) None of the above
6. Cellular foundations
The bacterium E. coli requires simple organic molecules for growth and energy—it is therefore a:
A) chemoautotroph.
B) chemoheterotroph.
C) lithotroph.
D) photoautotroph.
E) photoheterotroph.
7. Cellular foundations
Which is a list of organelles?
A) Mitochondria, chromatin, endoplasmic reticulum
B) Peroxisomes, lysosomes, plasma membrane
C) Proteasomes, peroxisomes, lysosomes
D) Mitochondria, endoplasmic reticulum, peroxisomes
E) All of the above
8. Cellular foundations
Which one of the following has the cellular components arranged in order of increasing size?
A) Amino acid < protein < mitochondrion < ribosome
B) Amino acid < protein < ribosome < mitochondrion
C) Amino acid < ribosome < protein < mitochondrion
D) Protein < amino acid < mitochondrion < ribosome
E) Protein < ribosome < mitochondrion < amino acid
9. Cellular foundations
The three-dimensional structure of macromolecules is formed and maintained primarily through
noncovalent interactions. Which one of the following is not considered a noncovalent interaction?
A) Carbon-carbon bonds
B) Hydrogen bonds
C) Hydrophobic interactions
D) Ionic interactions
E) van der Waals interactions
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10. Chemical foundations
Which one of the following is not among the four most abundant elements in living organisms?
A) Carbon
B) Hydrogen
C) Nitrogen
D) Oxygen
E) Phosphorus
11. Chemical foundations
The four covalent bonds in methane (CH4) are arranged around carbon to give which one of the
following geometries?
A) Linear
B) Tetrahedral
C) Trigonal bipyramidal
D) Trigonal planar
E) Trigonal pyramidal
12. Chemical foundations
What functional groups are present on this molecule?
A) Ether and aldehyde
B) Hydroxyl and aldehyde
C) Hydroxyl and carboxylic acid
D) Hydroxyl and ester
E) Hydroxyl and ketone
13. Chemical foundations
The macromolecules that serve in the storage and transmission of genetic information are:
A) carbohydrates.
B) lipids.
C) membranes.
D) nucleic acids.
E) proteins.
14. Chemical foundations
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Stereoisomers that are nonsuperimposable mirror images of each other are known as:
A) anomers.
B) cis-trans isomers.
C) diastereoisomers.
D) enantiomers.
E) geometric isomers.
15. Chemical Foundations
The catalog of all proteins functioning in a cell is the:
A) metabolome.
B) proteasome.
C) lysosome.
D) proteome.
E) genome.
16. Chemical foundations
Use the terms a) chemoautotrophs, b) chemoheterotrophs, c) photoautotrophs, and d)
photoheterotrophs and identify the answer that correctly finishes the statement:
Carnivores are and herbivores are .
A) b, c
B) b, d
C) b, b
D) a, b
E) a, a
17. Chemical foundations
The enzyme fumarase catalyzes the reversible hydration of fumaric acid to l-malate, but it will not
catalyze the hydration of maleic acid, the cis isomer of fumaric acid. This is an example of:
A) biological activity.
B) chiral activity.
C) racemization.
D) stereoisomerization.
E) stereospecificity.
18. Physical foundations
Humans maintain a nearly constant level of hemoglobin by continually synthesizing and degrading it.
This is an example of a(n):
A) dynamic steady state.
B) equilibrium state.
C) exergonic change.
D) free-energy change.
E) waste of energy.
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19. Physical foundations
If heat energy is absorbed by the system during a chemical reaction, the reaction is said to be:
A) at equilibrium.
B) endergonic.
C) endothermic.
D) exergonic.
E) exothermic.
20. Physical foundations
If the free energy change G for a reaction is –46.11 kJ/mol, the reaction is:
A) at equilibrium.
B) endergonic.
C) endothermic.
D) exergonic.
E) exothermic.
21. Physical foundations
The major carrier of chemical energy in all cells is:
A) acetyl triphosphate.
B) adenosine monophosphate.
C) adenosine triphosphate.
D) cytosine tetraphosphate.
E) uridine diphosphate.
22. Physical foundations
Enzymes are biological catalysts that enhance the rate of a reaction by:
A) decreasing the activation energy.
B) decreasing the amount of free energy released.
C) increasing the activation energy.
D) increasing the amount of free energy released.
E) increasing the energy of the transition state.
23. Physical foundations
Energy requiring metabolic pathways that yield complex molecules from simpler precursors are:
A) amphibolic.
B) anabolic.
C) autotrophic.
D) catabolic.
E) heterotrophic.
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24. Genetic foundations
Hereditary information (with the exception of some viruses) is preserved in:
A) deoxyribonucleic acid.
B) membrane structures.
C) nuclei.
D) polysaccharides.
E) ribonucleic acid.
25. Genetic foundations
When a region of DNA must be repaired by removing and replacing some of the nucleotides, what
ensures that the new nucleotides are in the correct sequence?
A) DNA cannot be repaired and this explains why mutations occur.
B) Specific enzymes bind the correct nucleotides.
C) The new nucleotides base pair accurately with those on the complementary strand.
D) The repair enzyme recognizes the removed nucleotide and brings in an identical one to replace it.
E) The three-dimensional structure determines the order of nucleotides.
26. Genetic foundations
The three-dimensional structure of a protein is determined primarily by:
A) electrostatic guidance from nucleic acid structure.
B) how many amino acids are in the protein.
C) hydrophobic interaction with lipids that provide a folding framework.
D) modification during interactions with ribosomes.
E) the sequence of amino acids in the protein.
27. Evolutionary foundations
According to Oparin’s theory for the origin of life, the prebiotic atmosphere:
A) already contained some primitive RNA molecules.
B) basically was very similar to the atmosphere of today.
C) contained many amino acids.
D) had an abundance of methane, ammonia, and water.
E) was rich in oxygen.
28. Evolutionary foundations
When two genes in an organism share detectable sequence similarity, those genes or their gene
products, are said to be:
A) homologues.
B) orthologues.
C) paralogues.
D) A and B.
E) A and C.
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F) B and C
Short Answer Questions
29. Cellular foundations
Pages: 1–2 Difficulty: 1
What six characteristics distinguish living organisms from inanimate objects?
30. Cellular foundations
Page: 3 Difficulty: 1
All cells are surrounded by a plasma membrane composed of lipid and protein molecules. What is
the function of the plasma membrane?
31. Cellular foundations
Page: 5 Difficulty: 1
E. coli is known as a gram-negative bacterial species. (a) How is this determined? (b) How do gram-
negative bacteria differ structurally from gram-positive bacteria?
32. Cellular foundations
Page: 6 Difficulty: 1
Most cells of higher plants have a cell wall outside the plasma membrane. What is the function of the
cell wall?
33. Cellular foundations
Page: 10 Difficulty: 2
(a) List the types of noncovalent interactions that are important in providing stability to the three–
dimensional structures of macromolecules. (b) Why is it important that these interactions be
noncovalent, rather than covalent, bonds?
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34. Cellular foundations
Page: 3 Difficulty: 2
What is the difference, if any, between cytosol and cytoplasm?
35. Cellular foundations
Page: 6 Difficulty: 2
Provide a brief explanation for the observation that macromolecules diffuse at a slower rate in the
cytosol than they do in dilute solution.
36. Chemical foundations
Page: 12 Difficulty: 1
Draw the structures of the following functional groups in their un-ionized forms:
(a) hydroxyl, (b) carboxyl, (c) amino, (d) phosphoryl.
37. Chemical foundations
Pages: 13–14 Difficulty: 2
What is the underlying, organizing biochemical principle that results in the chemical similarity of
virtually all living things? Given this biochemical similarity, how is the structural and functional
diversity of living things possible?
38. Chemical foundations
Page: 15 Difficulty: 2
Explain the difference, if any, between a proteome and a proteasome.
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39. Chemical foundations
Page: 14 Difficulty: 2
Name two functions of (a) proteins, (b) nucleic acids, (c) polysaccharides, (d) lipids.
40. Chemical Foundations
Page: 16 Difficulty: 2
Why is an asymmetric carbon atom called a chiral center?
41. Chemical foundations
Pages: 15–16, 18 Difficulty: 3
Differentiate between configuration and conformation.
42. Chemical foundations
Pages: 16–17 Difficulty: 3
(a) What is optical activity? (b) How did Louis Pasteur arrive at an explanation for the phenomenon
of optical activity?
43. Chemical foundations
Pages: 18–19 Difficulty: 3
A chemist working in a pharmaceutical lab synthesized a new drug as a racemic mixture. Why is it
important that she separate the two enantiomers and test each for its biological activity?
44. Chemical foundations
Page: 18 Difficulty: 3
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Explain why living organisms are able to produce particular chiral forms of different biomolceules
while laboratory chemical synthesis usually produces a racemic mixture.
45. Physical foundations
Page: 20 Difficulty: 2
Proteins are constantly being synthesized in a living cell. Why doesn’t the number of protein
molecules become too great for the cell to contain, leading to cell destruction?
46. Physical foundations
Page: 20 Difficulty: 2
Describe the relationship between a living organism and its surroundings in terms of both matter and
energy.
47. Physical foundations
Pages: 22–24 Difficulty: 2
The free-energy change for the formation of a protein from the individual amino acids is positive and
is thus an endergonic reaction. How, then, do cells accomplish this process?
48. Physical foundations
Pages: 22–24 Difficulty: 3
Instant cold packs get cold when the contents, usually solid urea and liquid water, are mixed,
producing an aqueous solution of urea. Although this process is clearly spontaneous, the products are
colder than the reactants. Explain how this is possible in terms of the difference between G and H.
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49. Physical foundations
Pages: 24–25 Difficulty: 2
(a) On the reaction coordinate diagram shown below, label the transition state and the overall free–
energy change (G) for the uncatalyzed reaction A → B. (b) Is this an exergonic or endergonic
reaction? (c) Draw a second curve showing the energetics of the reaction if it were enzyme–
catalyzed.
50. Physical foundations
Page: 26 Difficulty: 2
What is meant by feedback inhibition and why is it important in a living organism?
51. Genetic foundations
Pages: 27–29 Difficulty: 2
How is the genetic information encoded in DNA and how is a new copy of DNA synthesized?
52. Genetic foundations
Pages: 27–30 Difficulty: 3
Hereditary transmission of genetic information can be viewed as a balance between stability and
change. Explain.
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53. Genetic foundations
Pages: 29–30 Difficulty: 3
Discuss how a mutation in DNA could be harmful or beneficial to an organism.
54. Evolutionary foundations
Pages: 30–31 Difficulty: 3
Describe Stanley Miller’s experiment (1953) and its relevance.
55. Evolutionary foundations
Pages: 31–32 Difficulty: 2
Describe the “RNA world” hypothesis.
56. Evolutionary functions
Page: 32 Difficulty: 1
Describe how the rise of O2-producing bacteria might have led to the eventual predominance of
aerobic organisms on earth.
57. Evolutionary foundations
Page: 33 Difficulty: 2
What is meant by endosymbiotic association? How can this concept explain the evolution of
eukaryotic cells that are capable of carrying out photosynthesis and/or aerobic metabolism?