,CHEM212/CHEM 212 Module 1 Exam Biochemistry
1. A compound with a molecular mass of 1,000 g/mol is classified as which of the following based on
the module's definition?
A) A macromolecule, because it exceeds 500 g/mol
B) An oligomer, because it contains fewer than ten monomer units
C) A monomer, because it can serve as a building block
D) A supramolecular complex, because it assembles spontaneously
Correct Answer: An oligomer, because it contains fewer than ten monomer units
Rationale: Macromolecules in biochemistry are typically defined as very large biological polymers with
molecular masses in the tens of thousands of Daltons or more; 1,000 g/mol is too small. Oligomers
consist of a few monomer units and represent the intermediate scale between monomers and true
macromolecules. Monomers are single building blocks, while supramolecular complexes involve non-
covalent assembly of multiple macromolecules.
2. Which statement accurately describes the relationship between carbon's bonding capacity and the
diversity of biomolecules?
A) Carbon forms only single bonds, limiting molecular diversity to linear chains
B) Carbon's four valence electrons allow single, double, and triple bonds, enabling complex
architectures
C) Carbon bonds exclusively with hydrogen, restricting functional group variety
D) Carbon's ionic bonding with metals produces the structural framework of biomolecules
Correct Answer: Carbon's four valence electrons allow single, double, and triple bonds, enabling
complex architectures
Rationale: Carbon possesses four valence electrons, permitting it to form four covalent bonds in
various hybridization states (sp, sp2, sp3), which generates linear, branched, and cyclic structures. This
versatility is the foundation of organic chemistry and biomolecular diversity. The other options
incorrectly limit carbon's bonding capabilities or mischaracterize the nature of its bonds.
,3. The molecule responsible for the oxygen-carrying capacity of blood is best described as which type
of biomolecule?
A) A monosaccharide with a heme prosthetic group
B) A conjugated protein containing four globin chains and heme moieties
C) A steroid hormone derived from cholesterol
D) A fibrous protein composed of collagen triple helices
Correct Answer: A conjugated protein containing four globin chains and heme moieties
Rationale: Hemoglobin is a conjugated protein consisting of four globin polypeptide chains, each
bound to a heme prosthetic group containing iron. This quaternary structure enables cooperative
oxygen binding. Monosaccharides are carbohydrates, steroid hormones are lipids, and collagen is a
structural fibrous protein unrelated to oxygen transport.
4. Vitamin C exerts its biochemical effects primarily through which mechanism?
A) Acting as a cofactor for hydroxylation reactions in collagen synthesis
B) Serving as a primary electron carrier in the mitochondrial electron transport chain
C) Functioning as a lipid-soluble antioxidant in cell membranes
D) Catalyzing the phosphorylation of glucose in the cytoplasm
Correct Answer: Acting as a cofactor for hydroxylation reactions in collagen synthesis
Rationale: Vitamin C (ascorbic acid) is a water-soluble vitamin that serves as a reducing agent and
cofactor for prolyl and lysyl hydroxylases, enzymes required for collagen maturation. Its deficiency
leads to scurvy due to defective connective tissue. It is not a mitochondrial electron carrier, is water-
soluble rather than lipid-soluble, and does not phosphorylate glucose.
5. Which of the following best characterizes the structural organization of insulin?
A) A single polypeptide chain with no post-translational modifications
B) A disulfide-linked heterodimer of A and B chains derived from proinsulin
C) A tetrameric protein with four identical subunits
, D) A linear polysaccharide composed of glucose units
Correct Answer: A disulfide-linked heterodimer of A and B chains derived from proinsulin
Rationale: Insulin is synthesized as preproinsulin, processed to proinsulin, and then cleaved to yield
mature insulin consisting of A and B chains linked by disulfide bonds. It is not a single chain, not a
tetramer, and certainly not a polysaccharide. This processing pathway exemplifies post-translational
modification.
6. A molecule consisting of two to ten monosaccharide units linked by glycosidic bonds is classified as
which of the following?
A) A polysaccharide
B) An oligosaccharide
C) A monosaccharide
D) A supramolecular assembly
Correct Answer: An oligosaccharide
Rationale: Oligosaccharides are carbohydrates composed of a small number (typically 2–10) of
monosaccharide units. Polysaccharides contain many more units, monosaccharides are single sugars,
and supramolecular assemblies involve non-covalent clustering of macromolecules. This distinction is
fundamental to carbohydrate classification.
7. Which element is considered a bulk element in biological organisms?
A) Iron
B) Zinc
C) Carbon
D) Copper
Correct Answer: Carbon
1. A compound with a molecular mass of 1,000 g/mol is classified as which of the following based on
the module's definition?
A) A macromolecule, because it exceeds 500 g/mol
B) An oligomer, because it contains fewer than ten monomer units
C) A monomer, because it can serve as a building block
D) A supramolecular complex, because it assembles spontaneously
Correct Answer: An oligomer, because it contains fewer than ten monomer units
Rationale: Macromolecules in biochemistry are typically defined as very large biological polymers with
molecular masses in the tens of thousands of Daltons or more; 1,000 g/mol is too small. Oligomers
consist of a few monomer units and represent the intermediate scale between monomers and true
macromolecules. Monomers are single building blocks, while supramolecular complexes involve non-
covalent assembly of multiple macromolecules.
2. Which statement accurately describes the relationship between carbon's bonding capacity and the
diversity of biomolecules?
A) Carbon forms only single bonds, limiting molecular diversity to linear chains
B) Carbon's four valence electrons allow single, double, and triple bonds, enabling complex
architectures
C) Carbon bonds exclusively with hydrogen, restricting functional group variety
D) Carbon's ionic bonding with metals produces the structural framework of biomolecules
Correct Answer: Carbon's four valence electrons allow single, double, and triple bonds, enabling
complex architectures
Rationale: Carbon possesses four valence electrons, permitting it to form four covalent bonds in
various hybridization states (sp, sp2, sp3), which generates linear, branched, and cyclic structures. This
versatility is the foundation of organic chemistry and biomolecular diversity. The other options
incorrectly limit carbon's bonding capabilities or mischaracterize the nature of its bonds.
,3. The molecule responsible for the oxygen-carrying capacity of blood is best described as which type
of biomolecule?
A) A monosaccharide with a heme prosthetic group
B) A conjugated protein containing four globin chains and heme moieties
C) A steroid hormone derived from cholesterol
D) A fibrous protein composed of collagen triple helices
Correct Answer: A conjugated protein containing four globin chains and heme moieties
Rationale: Hemoglobin is a conjugated protein consisting of four globin polypeptide chains, each
bound to a heme prosthetic group containing iron. This quaternary structure enables cooperative
oxygen binding. Monosaccharides are carbohydrates, steroid hormones are lipids, and collagen is a
structural fibrous protein unrelated to oxygen transport.
4. Vitamin C exerts its biochemical effects primarily through which mechanism?
A) Acting as a cofactor for hydroxylation reactions in collagen synthesis
B) Serving as a primary electron carrier in the mitochondrial electron transport chain
C) Functioning as a lipid-soluble antioxidant in cell membranes
D) Catalyzing the phosphorylation of glucose in the cytoplasm
Correct Answer: Acting as a cofactor for hydroxylation reactions in collagen synthesis
Rationale: Vitamin C (ascorbic acid) is a water-soluble vitamin that serves as a reducing agent and
cofactor for prolyl and lysyl hydroxylases, enzymes required for collagen maturation. Its deficiency
leads to scurvy due to defective connective tissue. It is not a mitochondrial electron carrier, is water-
soluble rather than lipid-soluble, and does not phosphorylate glucose.
5. Which of the following best characterizes the structural organization of insulin?
A) A single polypeptide chain with no post-translational modifications
B) A disulfide-linked heterodimer of A and B chains derived from proinsulin
C) A tetrameric protein with four identical subunits
, D) A linear polysaccharide composed of glucose units
Correct Answer: A disulfide-linked heterodimer of A and B chains derived from proinsulin
Rationale: Insulin is synthesized as preproinsulin, processed to proinsulin, and then cleaved to yield
mature insulin consisting of A and B chains linked by disulfide bonds. It is not a single chain, not a
tetramer, and certainly not a polysaccharide. This processing pathway exemplifies post-translational
modification.
6. A molecule consisting of two to ten monosaccharide units linked by glycosidic bonds is classified as
which of the following?
A) A polysaccharide
B) An oligosaccharide
C) A monosaccharide
D) A supramolecular assembly
Correct Answer: An oligosaccharide
Rationale: Oligosaccharides are carbohydrates composed of a small number (typically 2–10) of
monosaccharide units. Polysaccharides contain many more units, monosaccharides are single sugars,
and supramolecular assemblies involve non-covalent clustering of macromolecules. This distinction is
fundamental to carbohydrate classification.
7. Which element is considered a bulk element in biological organisms?
A) Iron
B) Zinc
C) Carbon
D) Copper
Correct Answer: Carbon
