,Chapter 01: Biochemistry and the Unity of Life
1. What underlies the unity of biochemistry?
a. Some organisms are highly uniform at the molecular level.
b. All leaving beings are highly uniform at the organismal level.
c. Organisms are highly uniform at the cellular level.
d. All organisms are highly uniform at the molecular level.
e. Some leaving beings are highly uniform at the cellular level.
ANSWER: d
2. How many times more carbon is contained in organisms than in Earth's crust?
a. 60 times
b. 50 times
c. 9.5 times
d. 10 times
e. 100 times
ANSWER: b
3. Why is carbon preferable to be the chemical base for life?
a. Carbone dioxide is essentially insoluble in water.
b. It escapes the biochemical circulation once it is utilized.
c. The stability and strength of the carbon–carbon bonds make it a good base for larger molecular
complexes.
d. By reacting with hydrogen, it can undergo combustion, which provides organisms with energy.
e. Carbon dioxide is a strong construction material.
ANSWER: c
4. What is NOT a primary function of proteins?
a. signal receptors
b. energy storage
c. signal molecules
d. structural units
e. defensive agents
ANSWER: b
5. What does being a catalyst mean?
a. slowing down the rate of reactions to increase control over them
b. being fully utilized in the course of a reaction; causing no unnecessary change in the reaction
components
c. repeatedly enhancing the rate of chemical reactions without being consumed
d. repeatedly decreasing the rate of chemical reactions without being affected by enzymes
e. enhancing the rate of chemical reactions being permanently affected during their course to control
the environmental changes
ANSWER: c
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,6. Which structure CANNOT be a nucleotide?
a. a five-carbon sugar attached to a base and at least one phosphoryl group
b. a five-carbon sugar attached to a heterocyclic ring structure and one phosphoryl group
c. a five-carbon sugar attached to a base and two phosphoryl groups
d. a five-carbon sugar attached to a base and four phosphoryl groups
e. a five-carbon sugar attached to a heterocyclic ring structure and three phosphoryl groups
ANSWER: d
7. What determines the nature of an organism?
a. the information stored in proteins
b. the information contained in deoxyribonucleotides
c. the information stored in the deoxyribonucleic acid
d. the information stored in biological polymers
e. the information contained in the ribonucleic acid
ANSWER: c
8. What is NOT a nucleotide?
a. adenine
b. thymine
c. uracil
d. cytosine
e. adenosine
ANSWER: e
9. Which statement about compositional differences between DNA and RNA is TRUE?
a. Ribonucleotides contain an additional hydroxyl group.
b. Ribonucleotides exploit three different bases, while deoxyribonucleotides exploit four.
c. Deoxyribonucleotides contain an additional hydroxyl group.
d. Deoxyribonucleotides contain a five-carbon sugar, whereas RNA bases contain a six-carbon sugar.
e. Ribonucleotides exploit four different bases, while deoxyribonucleotides exploit tree.
ANSWER: a
10. What is the molecular basis for establishing intracellular compartments?
a. the formation of membranous barriers due to ability of proteins to form extended linear structures
b. the ability of lipids to form barriers due to their dual properties regarding solubility in water
c. the formation of lipid barriers due to the small size of lipids
d. the development of lipid barriers due to hydrophilic interactions within lipid molecules
e. the formation of lipid barriers due to the dual nature of lipids regarding their interactions with
proteins
ANSWER: b
11. What can serve as sites of cell-to-cell interactions?
a. molecules of glycogen
b. branched chains of carbohydrates
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, c. branched proteins
d. hydrophobic tails of lipids
e. hydrophilic heads of lipids
ANSWER: b
12. Choose the CORRECT statement about functions of lipids and proteins.
a. They both can be involved in signal transduction.
b. They both form a cell skeleton.
c. They both act as receptors for signal molecules.
d. They both can provide large amounts of cellular energy upon combustion.
e. They both are involved in the transfer of biological information.
ANSWER: a
13. What determines the function of a cell or tissue?
a. information contained in the genome
b. selective transcription of RNA
c. translation of RNA
d. replication of DNA
e. selective expression of genes
ANSWER: e
14. What is the central dogma?
a. the flow of information across all biomolecules of a cell
b. the scheme proposed by Francis Crick to describe complex cell-to-cell interactions
c. the basic scheme of the flow of information in the cell for eventual rendering of the genetic
information into a functional form
d. the scheme proposed in 1958 to describe the genome
e. the basic scheme of selective replication of DNA
ANSWER: c
15. What is the basic unit of life?
a. DNA
b. protein
c. RNA
d. cell
e. biomolecular complexes
ANSWER: d
16. What constitutes the cell membrane?
a. a lipid bilayer organized through interaction of lipid hydrophobic heads with each other and lipid
hydrophilic tails with the environment
b. the outer layer of a cytoplasm
c. a lipid bilayer organized through interaction of lipid hydrophobic tails with each other and lipid
hydrophilic heads with an aqueous environment
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1. What underlies the unity of biochemistry?
a. Some organisms are highly uniform at the molecular level.
b. All leaving beings are highly uniform at the organismal level.
c. Organisms are highly uniform at the cellular level.
d. All organisms are highly uniform at the molecular level.
e. Some leaving beings are highly uniform at the cellular level.
ANSWER: d
2. How many times more carbon is contained in organisms than in Earth's crust?
a. 60 times
b. 50 times
c. 9.5 times
d. 10 times
e. 100 times
ANSWER: b
3. Why is carbon preferable to be the chemical base for life?
a. Carbone dioxide is essentially insoluble in water.
b. It escapes the biochemical circulation once it is utilized.
c. The stability and strength of the carbon–carbon bonds make it a good base for larger molecular
complexes.
d. By reacting with hydrogen, it can undergo combustion, which provides organisms with energy.
e. Carbon dioxide is a strong construction material.
ANSWER: c
4. What is NOT a primary function of proteins?
a. signal receptors
b. energy storage
c. signal molecules
d. structural units
e. defensive agents
ANSWER: b
5. What does being a catalyst mean?
a. slowing down the rate of reactions to increase control over them
b. being fully utilized in the course of a reaction; causing no unnecessary change in the reaction
components
c. repeatedly enhancing the rate of chemical reactions without being consumed
d. repeatedly decreasing the rate of chemical reactions without being affected by enzymes
e. enhancing the rate of chemical reactions being permanently affected during their course to control
the environmental changes
ANSWER: c
_____________________________________________________________________________________________
1|Page
.
,6. Which structure CANNOT be a nucleotide?
a. a five-carbon sugar attached to a base and at least one phosphoryl group
b. a five-carbon sugar attached to a heterocyclic ring structure and one phosphoryl group
c. a five-carbon sugar attached to a base and two phosphoryl groups
d. a five-carbon sugar attached to a base and four phosphoryl groups
e. a five-carbon sugar attached to a heterocyclic ring structure and three phosphoryl groups
ANSWER: d
7. What determines the nature of an organism?
a. the information stored in proteins
b. the information contained in deoxyribonucleotides
c. the information stored in the deoxyribonucleic acid
d. the information stored in biological polymers
e. the information contained in the ribonucleic acid
ANSWER: c
8. What is NOT a nucleotide?
a. adenine
b. thymine
c. uracil
d. cytosine
e. adenosine
ANSWER: e
9. Which statement about compositional differences between DNA and RNA is TRUE?
a. Ribonucleotides contain an additional hydroxyl group.
b. Ribonucleotides exploit three different bases, while deoxyribonucleotides exploit four.
c. Deoxyribonucleotides contain an additional hydroxyl group.
d. Deoxyribonucleotides contain a five-carbon sugar, whereas RNA bases contain a six-carbon sugar.
e. Ribonucleotides exploit four different bases, while deoxyribonucleotides exploit tree.
ANSWER: a
10. What is the molecular basis for establishing intracellular compartments?
a. the formation of membranous barriers due to ability of proteins to form extended linear structures
b. the ability of lipids to form barriers due to their dual properties regarding solubility in water
c. the formation of lipid barriers due to the small size of lipids
d. the development of lipid barriers due to hydrophilic interactions within lipid molecules
e. the formation of lipid barriers due to the dual nature of lipids regarding their interactions with
proteins
ANSWER: b
11. What can serve as sites of cell-to-cell interactions?
a. molecules of glycogen
b. branched chains of carbohydrates
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.
, c. branched proteins
d. hydrophobic tails of lipids
e. hydrophilic heads of lipids
ANSWER: b
12. Choose the CORRECT statement about functions of lipids and proteins.
a. They both can be involved in signal transduction.
b. They both form a cell skeleton.
c. They both act as receptors for signal molecules.
d. They both can provide large amounts of cellular energy upon combustion.
e. They both are involved in the transfer of biological information.
ANSWER: a
13. What determines the function of a cell or tissue?
a. information contained in the genome
b. selective transcription of RNA
c. translation of RNA
d. replication of DNA
e. selective expression of genes
ANSWER: e
14. What is the central dogma?
a. the flow of information across all biomolecules of a cell
b. the scheme proposed by Francis Crick to describe complex cell-to-cell interactions
c. the basic scheme of the flow of information in the cell for eventual rendering of the genetic
information into a functional form
d. the scheme proposed in 1958 to describe the genome
e. the basic scheme of selective replication of DNA
ANSWER: c
15. What is the basic unit of life?
a. DNA
b. protein
c. RNA
d. cell
e. biomolecular complexes
ANSWER: d
16. What constitutes the cell membrane?
a. a lipid bilayer organized through interaction of lipid hydrophobic heads with each other and lipid
hydrophilic tails with the environment
b. the outer layer of a cytoplasm
c. a lipid bilayer organized through interaction of lipid hydrophobic tails with each other and lipid
hydrophilic heads with an aqueous environment
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