BIOL180 Lesson 3 Quiz Biomolecules
and Enzymes Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which statement best describes a biomolecule?
A. A molecule found only inside the nucleus
B. A molecule produced exclusively by plants
C. A molecule that is produced by or associated with living
organisms
D. A molecule that contains only carbon and hydrogen
Answer: C. A molecule that is produced by or associated with living
organisms
Rationale: Biomolecules are chemical compounds associated with
living systems. Major biological biomolecules include carbohydrates,
lipids, proteins, and nucleic acids. Although many biomolecules
contain carbon, they are not all composed exclusively of carbon and
hydrogen, and they are not restricted to the nucleus or to plants.
2. Which four groups are generally considered the major classes of
biological macromolecules?
A. Vitamins, minerals, water, and salts
B. Carbohydrates, lipids, proteins, and nucleic acids
C. Glucose, ATP, DNA, and oxygen
D. Enzymes, hormones, ions, and gases
,Answer: B. Carbohydrates, lipids, proteins, and nucleic acids
Rationale: The four major classes of biological macromolecules are
carbohydrates, lipids, proteins, and nucleic acids. Each class has
characteristic structures and biological functions. Vitamins, minerals,
water, and salts are biologically important but are not classified as the
four major macromolecular classes.
3. Which element forms the structural backbone of most organic
molecules?
A. Sodium
B. Calcium
C. Phosphorus
D. Carbon
Answer: D. Carbon
Rationale: Carbon is the central structural element of organic
chemistry because it can form four covalent bonds and create chains,
branches, and rings. This versatility allows carbon to form the
complex molecular structures required for biological systems.
4. Why is carbon particularly well suited to forming biological
molecules?
A. It can form only ionic bonds
B. It cannot bond with itself
C. It can form four covalent bonds with a variety of atoms
D. It always forms molecules with four oxygen atoms
Answer: C. It can form four covalent bonds with a variety of atoms
Rationale: Carbon has four valence electrons and can form four stable
covalent bonds. It can bond with other carbon atoms as well as
,hydrogen, oxygen, nitrogen, phosphorus, sulfur, and other elements,
producing an enormous variety of biological molecules.
5. Which process joins monomers together to form a larger polymer
while removing water?
A. Hydrolysis
B. Oxidation
C. Ionization
D. Dehydration synthesis
Answer: D. Dehydration synthesis
Rationale: Dehydration synthesis, also called condensation, links
smaller molecules by forming a covalent bond while removing a
molecule of water. Hydrolysis is essentially the reverse process because
it uses water to break certain covalent bonds in polymers.
6. Which process uses water to break a covalent bond between
biological subunits?
A. Hydrolysis
B. Dehydration synthesis
C. Reduction
D. Phosphorylation
Answer: A. Hydrolysis
Rationale: Hydrolysis means “splitting with water.” During hydrolysis,
water participates in breaking a covalent bond, allowing a polymer or
larger molecule to be separated into smaller components. Digestion
commonly involves hydrolysis reactions.
7. Which carbohydrate is classified as a monosaccharide?
, A. Sucrose
B. Glycogen
C. Glucose
D. Starch
Answer: C. Glucose
Rationale: Glucose is a six-carbon monosaccharide and an important
cellular energy source. Sucrose is a disaccharide, while starch and
glycogen are polysaccharides composed of many sugar units.
8. Which molecule is a disaccharide?
A. Glycogen
B. Sucrose
C. Glucose
D. Cellulose
Answer: B. Sucrose
Rationale: Sucrose is a disaccharide composed of glucose and fructose.
Disaccharides contain two monosaccharide units joined by a
glycosidic bond. Glucose and fructose are monosaccharides, whereas
glycogen and cellulose are polysaccharides.
9. What is the primary function of carbohydrates in many cells?
A. Storing genetic information
B. Catalyzing every chemical reaction
C. Forming antibodies exclusively
D. Providing readily accessible energy
Answer: D. Providing readily accessible energy
Rationale: Carbohydrates are especially important as an accessible
energy source. Glucose can be metabolized through cellular pathways
and Enzymes Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which statement best describes a biomolecule?
A. A molecule found only inside the nucleus
B. A molecule produced exclusively by plants
C. A molecule that is produced by or associated with living
organisms
D. A molecule that contains only carbon and hydrogen
Answer: C. A molecule that is produced by or associated with living
organisms
Rationale: Biomolecules are chemical compounds associated with
living systems. Major biological biomolecules include carbohydrates,
lipids, proteins, and nucleic acids. Although many biomolecules
contain carbon, they are not all composed exclusively of carbon and
hydrogen, and they are not restricted to the nucleus or to plants.
2. Which four groups are generally considered the major classes of
biological macromolecules?
A. Vitamins, minerals, water, and salts
B. Carbohydrates, lipids, proteins, and nucleic acids
C. Glucose, ATP, DNA, and oxygen
D. Enzymes, hormones, ions, and gases
,Answer: B. Carbohydrates, lipids, proteins, and nucleic acids
Rationale: The four major classes of biological macromolecules are
carbohydrates, lipids, proteins, and nucleic acids. Each class has
characteristic structures and biological functions. Vitamins, minerals,
water, and salts are biologically important but are not classified as the
four major macromolecular classes.
3. Which element forms the structural backbone of most organic
molecules?
A. Sodium
B. Calcium
C. Phosphorus
D. Carbon
Answer: D. Carbon
Rationale: Carbon is the central structural element of organic
chemistry because it can form four covalent bonds and create chains,
branches, and rings. This versatility allows carbon to form the
complex molecular structures required for biological systems.
4. Why is carbon particularly well suited to forming biological
molecules?
A. It can form only ionic bonds
B. It cannot bond with itself
C. It can form four covalent bonds with a variety of atoms
D. It always forms molecules with four oxygen atoms
Answer: C. It can form four covalent bonds with a variety of atoms
Rationale: Carbon has four valence electrons and can form four stable
covalent bonds. It can bond with other carbon atoms as well as
,hydrogen, oxygen, nitrogen, phosphorus, sulfur, and other elements,
producing an enormous variety of biological molecules.
5. Which process joins monomers together to form a larger polymer
while removing water?
A. Hydrolysis
B. Oxidation
C. Ionization
D. Dehydration synthesis
Answer: D. Dehydration synthesis
Rationale: Dehydration synthesis, also called condensation, links
smaller molecules by forming a covalent bond while removing a
molecule of water. Hydrolysis is essentially the reverse process because
it uses water to break certain covalent bonds in polymers.
6. Which process uses water to break a covalent bond between
biological subunits?
A. Hydrolysis
B. Dehydration synthesis
C. Reduction
D. Phosphorylation
Answer: A. Hydrolysis
Rationale: Hydrolysis means “splitting with water.” During hydrolysis,
water participates in breaking a covalent bond, allowing a polymer or
larger molecule to be separated into smaller components. Digestion
commonly involves hydrolysis reactions.
7. Which carbohydrate is classified as a monosaccharide?
, A. Sucrose
B. Glycogen
C. Glucose
D. Starch
Answer: C. Glucose
Rationale: Glucose is a six-carbon monosaccharide and an important
cellular energy source. Sucrose is a disaccharide, while starch and
glycogen are polysaccharides composed of many sugar units.
8. Which molecule is a disaccharide?
A. Glycogen
B. Sucrose
C. Glucose
D. Cellulose
Answer: B. Sucrose
Rationale: Sucrose is a disaccharide composed of glucose and fructose.
Disaccharides contain two monosaccharide units joined by a
glycosidic bond. Glucose and fructose are monosaccharides, whereas
glycogen and cellulose are polysaccharides.
9. What is the primary function of carbohydrates in many cells?
A. Storing genetic information
B. Catalyzing every chemical reaction
C. Forming antibodies exclusively
D. Providing readily accessible energy
Answer: D. Providing readily accessible energy
Rationale: Carbohydrates are especially important as an accessible
energy source. Glucose can be metabolized through cellular pathways
