CHEM 121 Foundations of Biochemistry and Nuclear Chemistry Exam
2026/2027 UPDATE
1. Which of the following is the general empirical formula for most
monosaccharides?
A. CnHnOn
B. CnH2nOn
C. C2nHnOn
D. CnH2nO2n
Answer: B
Rationale: Most monosaccharides follow the empirical formula (CH2O)n, which can be
written as CnH2nOn.
2. A chiral carbon atom is defined as a carbon atom bonded to:
A. Four identical groups
B. Four different groups
C. Two different groups and a double bond
D. Three different groups
Answer: B
Rationale: Chirality in carbon requires four unique substituents attached to the central
carbon atom.
,3. Which disaccharide is composed of one glucose unit and one fructose unit?
A. Lactose
B. Maltose
C. Sucrose
D. Cellobiose
Answer: C
Rationale: Sucrose, or common table sugar, is formed by a glycosidic bond between
glucose and fructose.
4. Glycogen is a highly branched polymer of glucose used for energy storage in:
A. Plants
B. Animals
C. Bacteria
D. Viruses
Answer: B
Rationale: Glycogen is the primary storage form of glucose in animal tissues, particularly
the liver and muscles.
5. The linkage between two monosaccharides in a polysaccharide is called a:
A. Peptide bond
B. Ester bond
C. Glycosidic bond
D. Phosphodiester bond
Answer: C
Rationale: Monosaccharides are linked together via glycosidic bonds formed through
dehydration reactions.
, 6. Which of the following is a non-reducing sugar?
A. Sucrose
B. Fructose
C. Galactose
D. Glucose
Answer: A
Rationale: Sucrose is a non-reducing sugar because the glycosidic bond involves the
anomeric carbons of both glucose and fructose.
7. Lipids are primarily characterized by their:
A. High solubility in water
B. Role as catalysts in chemical reactions
C. Ability to form long chains of amino acids
D. Insolubility in water and solubility in nonpolar solvents
Answer: D
Rationale: Lipids are hydrophobic molecules that do not dissolve well in water but are
soluble in organic solvents.
8. A saturated fatty acid contains:
A. At least one double bond
B. Triple bonds between carbon atoms
C. No double bonds between carbon atoms
D. Only aromatic rings
Answer: C
Rationale: Saturated fats have ‘saturated’ their carbon chains with hydrogen, meaning
they contain only single bonds.
2026/2027 UPDATE
1. Which of the following is the general empirical formula for most
monosaccharides?
A. CnHnOn
B. CnH2nOn
C. C2nHnOn
D. CnH2nO2n
Answer: B
Rationale: Most monosaccharides follow the empirical formula (CH2O)n, which can be
written as CnH2nOn.
2. A chiral carbon atom is defined as a carbon atom bonded to:
A. Four identical groups
B. Four different groups
C. Two different groups and a double bond
D. Three different groups
Answer: B
Rationale: Chirality in carbon requires four unique substituents attached to the central
carbon atom.
,3. Which disaccharide is composed of one glucose unit and one fructose unit?
A. Lactose
B. Maltose
C. Sucrose
D. Cellobiose
Answer: C
Rationale: Sucrose, or common table sugar, is formed by a glycosidic bond between
glucose and fructose.
4. Glycogen is a highly branched polymer of glucose used for energy storage in:
A. Plants
B. Animals
C. Bacteria
D. Viruses
Answer: B
Rationale: Glycogen is the primary storage form of glucose in animal tissues, particularly
the liver and muscles.
5. The linkage between two monosaccharides in a polysaccharide is called a:
A. Peptide bond
B. Ester bond
C. Glycosidic bond
D. Phosphodiester bond
Answer: C
Rationale: Monosaccharides are linked together via glycosidic bonds formed through
dehydration reactions.
, 6. Which of the following is a non-reducing sugar?
A. Sucrose
B. Fructose
C. Galactose
D. Glucose
Answer: A
Rationale: Sucrose is a non-reducing sugar because the glycosidic bond involves the
anomeric carbons of both glucose and fructose.
7. Lipids are primarily characterized by their:
A. High solubility in water
B. Role as catalysts in chemical reactions
C. Ability to form long chains of amino acids
D. Insolubility in water and solubility in nonpolar solvents
Answer: D
Rationale: Lipids are hydrophobic molecules that do not dissolve well in water but are
soluble in organic solvents.
8. A saturated fatty acid contains:
A. At least one double bond
B. Triple bonds between carbon atoms
C. No double bonds between carbon atoms
D. Only aromatic rings
Answer: C
Rationale: Saturated fats have ‘saturated’ their carbon chains with hydrogen, meaning
they contain only single bonds.
