1
MCB63X PRINCIPLES OF BIOCHEMISTRY WITH THE BEST
SOLUTION QUESTIONS AND ANSWER VERIFIED/APPROVED
BEST GRADED A+ 2025/2026
1. The genetic information present in DNA is described by
A. the base composition of the DNA.
B. the sugar-phosphate backbone structure of the DNA.
C. the sequence of bases along a DNA strand.
D. the presence of base-pairing between the DNA strands. - answers-the sequence of bases along a
DNA strand.
2. The three-dimensional structure of a protein is specified by
A. other proteins that assist it in folding correctly.
B. its amino acid sequence and environment.
C. interaction of the newly synthesized protein with the portion of DNA that encoded it.
D. the temperature during its synthesis. - answers-its amino acid sequence and environment.
3. Biological macromolecules can be divided into four different classes.
Which type of molecule is NOT a major class of biological macromolecules?
A. nucleic acids
B. lipids
C. fatty acids
D. carbohydrates - answers-fatty acids
4. What is the MOST abundant element in human beings by percentage of total atoms?
A. hydrogen
B. oxygen
C. nitrogen
D. carbon - answers-hydrogen
5. Which statement is yes of carbon-based molecules and silicon-based molecules?
A. Both carbon and silicon can form four covalent bonds.
, 2
B. A silicon-silicon bond is stronger than a carbon-carbon bond.
C. Carbon can be combusted, whereas silicon cannot.
D. All three statements are true. - answers-Both carbon and silicon can form four covalent bonds.
6. What happens during transcription?
A. DNA serves as the template for a new molecule of DNA.
B. DNA serves as the template for a new molecule of RNA.
C. RNA serves as the template for a new molecule of protein.
D. RNA serves as the template for a new molecule of RNA. - answers-DNA serves as the template for
a new molecule of RNA.
7. In what year did Francis Crick propose the scheme that underlies information processing at the
level of gene expression?
A. 1890
B. 1925
C. 1958
D. 1979 - answers-1958
8. What is the main difference between a prokaryotic cell and a eukaryotic cell?
A. Prokaryotic cells do not contain membranes.
B. Eukaryotic cells have a periplasmic space.
C. Eukaryotic cells have membrane-enclosed compartments.
D. Prokaryotic cells do not contain DNA. - answers-Eukaryotic cells have membrane-enclosed
compartments.
1. Water is said to be highly cohesive because water molecules interact with one another through
A. van der Waals interactions.
B. hydrogen bonds.
C. covalent bonds.
D. hydrophobic interactions. - answers-hydrogen bonds.
2. A biological molecule can serve as a hydrogen bond donor if the hydrogen is attached to
, 3
A. oxygen or nitrogen.
B. any nonmetallic atom.
C. carbon.
D. carbon in aromatic groups. - answers-oxygen or nitrogen.
3. The second law of thermodynamics states that a spontaneous process
A. only increases the entropy of the system.
B. only increases the entropy of a system's surroundings.
C. increases the total entropy of a system plus its surroundings.
D. decreases the total entropy of a system plus its surroundings. - answers-increases the total
entropy of a system plus its surroundings.
4. The dielectric constant of the interior of a protein is considerably smaller than that of water. How
would this difference in dielectric constants affect the strength of an electrostatic interaction
between two opposite charges with the same distance between them if the charged groups were
located in the interior of the protein rather than on its surface?
The strength of the electrostatic interaction would be
A. stronger if the interacting charges were on the surface of the protein.
B. stronger if the interacting charges were in the interior of the protein.
C. independent of the charges' location in the protein.
D. stronger if one of the interacting charges was on the surface of the protein and the other was in
the interior. - answers-stronger if the interacting charges were in the interior of the protein.
5. Which statement is no of Brownian motion?
A. It is due to the random fluctuation of the energy content of the environment.
B. It is due to thermal noise.
C. It causes the random movement of pollen granules suspended in water.
D. It is independent of temperature. - answers-It is independent of temperature.
6. The partially positively charged hydrogen atoms of one water molecule can interact with the
partially negatively charged oxygen atoms of another water molecule.
This interaction between water molecules is called
A. a water bond.
, 4
B. a hydrogen bond.
C. both a water bond and Brownian motion.
D. both a hydrogen bond and Brownian motion. - answers-a hydrogen bond.
7. Which pair of terms describes molecules that can dissolve in water?
A. polar and hydrophilic
B. nonpolar and hydrophobic
C. polar and hydrophobic
D. nonpolar and hydrophilic - answers-polar and hydrophilic
8. Which bond or interaction is considered covalent?
A. a van der Waals interaction
B. a hydrogen bond
C. a disulfide bond
D. an ionic bond - answers-a disulfide bond
1. Which statement is true of the chirality of amino acids found in proteins?
A. Only L amino acids are found in proteins.
B. Only D amino acids are found in proteins.
C. Proteins contain both D and L amino acids.
D. D amino acids alternate with L amino acids in certain regions of proteins. - answers-Only L amino
acids are found in proteins.
2. Of the 20 amino acids that make up proteins, which is most likely to be present with its R group in
a mixture of ionization states near physiological pH?
A. Tyr
B. His
C. Glu
D. Gly - answers-His
3. For the peptide Ala-Arg-Lys-Ala-Asn-Ser-Ala-Ser, what would be the expected charges at pH 1,
7,and 13?
MCB63X PRINCIPLES OF BIOCHEMISTRY WITH THE BEST
SOLUTION QUESTIONS AND ANSWER VERIFIED/APPROVED
BEST GRADED A+ 2025/2026
1. The genetic information present in DNA is described by
A. the base composition of the DNA.
B. the sugar-phosphate backbone structure of the DNA.
C. the sequence of bases along a DNA strand.
D. the presence of base-pairing between the DNA strands. - answers-the sequence of bases along a
DNA strand.
2. The three-dimensional structure of a protein is specified by
A. other proteins that assist it in folding correctly.
B. its amino acid sequence and environment.
C. interaction of the newly synthesized protein with the portion of DNA that encoded it.
D. the temperature during its synthesis. - answers-its amino acid sequence and environment.
3. Biological macromolecules can be divided into four different classes.
Which type of molecule is NOT a major class of biological macromolecules?
A. nucleic acids
B. lipids
C. fatty acids
D. carbohydrates - answers-fatty acids
4. What is the MOST abundant element in human beings by percentage of total atoms?
A. hydrogen
B. oxygen
C. nitrogen
D. carbon - answers-hydrogen
5. Which statement is yes of carbon-based molecules and silicon-based molecules?
A. Both carbon and silicon can form four covalent bonds.
, 2
B. A silicon-silicon bond is stronger than a carbon-carbon bond.
C. Carbon can be combusted, whereas silicon cannot.
D. All three statements are true. - answers-Both carbon and silicon can form four covalent bonds.
6. What happens during transcription?
A. DNA serves as the template for a new molecule of DNA.
B. DNA serves as the template for a new molecule of RNA.
C. RNA serves as the template for a new molecule of protein.
D. RNA serves as the template for a new molecule of RNA. - answers-DNA serves as the template for
a new molecule of RNA.
7. In what year did Francis Crick propose the scheme that underlies information processing at the
level of gene expression?
A. 1890
B. 1925
C. 1958
D. 1979 - answers-1958
8. What is the main difference between a prokaryotic cell and a eukaryotic cell?
A. Prokaryotic cells do not contain membranes.
B. Eukaryotic cells have a periplasmic space.
C. Eukaryotic cells have membrane-enclosed compartments.
D. Prokaryotic cells do not contain DNA. - answers-Eukaryotic cells have membrane-enclosed
compartments.
1. Water is said to be highly cohesive because water molecules interact with one another through
A. van der Waals interactions.
B. hydrogen bonds.
C. covalent bonds.
D. hydrophobic interactions. - answers-hydrogen bonds.
2. A biological molecule can serve as a hydrogen bond donor if the hydrogen is attached to
, 3
A. oxygen or nitrogen.
B. any nonmetallic atom.
C. carbon.
D. carbon in aromatic groups. - answers-oxygen or nitrogen.
3. The second law of thermodynamics states that a spontaneous process
A. only increases the entropy of the system.
B. only increases the entropy of a system's surroundings.
C. increases the total entropy of a system plus its surroundings.
D. decreases the total entropy of a system plus its surroundings. - answers-increases the total
entropy of a system plus its surroundings.
4. The dielectric constant of the interior of a protein is considerably smaller than that of water. How
would this difference in dielectric constants affect the strength of an electrostatic interaction
between two opposite charges with the same distance between them if the charged groups were
located in the interior of the protein rather than on its surface?
The strength of the electrostatic interaction would be
A. stronger if the interacting charges were on the surface of the protein.
B. stronger if the interacting charges were in the interior of the protein.
C. independent of the charges' location in the protein.
D. stronger if one of the interacting charges was on the surface of the protein and the other was in
the interior. - answers-stronger if the interacting charges were in the interior of the protein.
5. Which statement is no of Brownian motion?
A. It is due to the random fluctuation of the energy content of the environment.
B. It is due to thermal noise.
C. It causes the random movement of pollen granules suspended in water.
D. It is independent of temperature. - answers-It is independent of temperature.
6. The partially positively charged hydrogen atoms of one water molecule can interact with the
partially negatively charged oxygen atoms of another water molecule.
This interaction between water molecules is called
A. a water bond.
, 4
B. a hydrogen bond.
C. both a water bond and Brownian motion.
D. both a hydrogen bond and Brownian motion. - answers-a hydrogen bond.
7. Which pair of terms describes molecules that can dissolve in water?
A. polar and hydrophilic
B. nonpolar and hydrophobic
C. polar and hydrophobic
D. nonpolar and hydrophilic - answers-polar and hydrophilic
8. Which bond or interaction is considered covalent?
A. a van der Waals interaction
B. a hydrogen bond
C. a disulfide bond
D. an ionic bond - answers-a disulfide bond
1. Which statement is true of the chirality of amino acids found in proteins?
A. Only L amino acids are found in proteins.
B. Only D amino acids are found in proteins.
C. Proteins contain both D and L amino acids.
D. D amino acids alternate with L amino acids in certain regions of proteins. - answers-Only L amino
acids are found in proteins.
2. Of the 20 amino acids that make up proteins, which is most likely to be present with its R group in
a mixture of ionization states near physiological pH?
A. Tyr
B. His
C. Glu
D. Gly - answers-His
3. For the peptide Ala-Arg-Lys-Ala-Asn-Ser-Ala-Ser, what would be the expected charges at pH 1,
7,and 13?
