,CHEM 210 Exam 6 | Biochemistry Exam Q&A
| Portage Learning
1. Which two types of nucleic acid are primarily responsible for storing and expressing
genetic information?
A) Proteins and lipids
B) DNA and RNA
C) Glycogen and starch
D) ATP and glucose
Correct Answer: DNA and RNA
Rationale: DNA serves as the principal long-term repository of hereditary information,
while RNA participates in information transfer, protein synthesis, regulation, and other
cellular processes. Proteins and lipids are not nucleic acids, and glycogen and starch are
carbohydrates. ATP and glucose are not nucleic acids either.
2. What is the basic monomeric unit of a nucleic acid polymer?
A) Amino acid
B) Fatty acid
C) Nucleotide
D) Monosaccharide
Correct Answer: Nucleotide
,Rationale: Nucleic acids are polymers composed of nucleotide residues. Each
nucleotide contains a nitrogenous base, a pentose sugar, and one or more phosphate
groups. Amino acids are the monomers of proteins, fatty acids are components of lipids,
and monosaccharides are the monomers of carbohydrates.
3. Which three components make up a typical nucleotide?
A) Glycerol, fatty acid, phosphate
B) Sugar, nitrogenous base, phosphate
C) Sugar, amino acid, phosphate
D) Base, glycerol, amino acid
Correct Answer: Sugar, nitrogenous base, phosphate
Rationale: A nucleotide consists of a pentose sugar, nitrogen-containing base, and
phosphate group. The combination of sugar and base alone is called a nucleoside.
Glycerol and fatty acids are components of lipids, and amino acids are the building
blocks of proteins.
4. A nucleoside differs from a nucleotide because a nucleoside lacks which component?
A) Nitrogenous base
B) Pentose sugar
C) Phosphate group
D) Carbon atoms
Correct Answer: Phosphate group
, Rationale: A nucleoside consists of a nitrogenous base linked to a pentose sugar.
Addition of one or more phosphate groups produces a nucleotide. Without the
phosphate group, the molecule is a nucleoside, not a nucleotide.
5. Which pentose sugar is found in DNA?
A) Ribose
B) Deoxyribose
C) Fructose
D) Glucose
Correct Answer: Deoxyribose
Rationale: DNA contains 2-deoxyribose. The absence of the 2' hydroxyl group
distinguishes deoxyribose from ribose and contributes to important chemical
differences between DNA and RNA. Fructose and glucose are hexoses, not pentoses.
6. Which pentose sugar is characteristic of RNA?
A) Ribose
B) Deoxyribose
C) Galactose
D) Mannose
Correct Answer: Ribose
| Portage Learning
1. Which two types of nucleic acid are primarily responsible for storing and expressing
genetic information?
A) Proteins and lipids
B) DNA and RNA
C) Glycogen and starch
D) ATP and glucose
Correct Answer: DNA and RNA
Rationale: DNA serves as the principal long-term repository of hereditary information,
while RNA participates in information transfer, protein synthesis, regulation, and other
cellular processes. Proteins and lipids are not nucleic acids, and glycogen and starch are
carbohydrates. ATP and glucose are not nucleic acids either.
2. What is the basic monomeric unit of a nucleic acid polymer?
A) Amino acid
B) Fatty acid
C) Nucleotide
D) Monosaccharide
Correct Answer: Nucleotide
,Rationale: Nucleic acids are polymers composed of nucleotide residues. Each
nucleotide contains a nitrogenous base, a pentose sugar, and one or more phosphate
groups. Amino acids are the monomers of proteins, fatty acids are components of lipids,
and monosaccharides are the monomers of carbohydrates.
3. Which three components make up a typical nucleotide?
A) Glycerol, fatty acid, phosphate
B) Sugar, nitrogenous base, phosphate
C) Sugar, amino acid, phosphate
D) Base, glycerol, amino acid
Correct Answer: Sugar, nitrogenous base, phosphate
Rationale: A nucleotide consists of a pentose sugar, nitrogen-containing base, and
phosphate group. The combination of sugar and base alone is called a nucleoside.
Glycerol and fatty acids are components of lipids, and amino acids are the building
blocks of proteins.
4. A nucleoside differs from a nucleotide because a nucleoside lacks which component?
A) Nitrogenous base
B) Pentose sugar
C) Phosphate group
D) Carbon atoms
Correct Answer: Phosphate group
, Rationale: A nucleoside consists of a nitrogenous base linked to a pentose sugar.
Addition of one or more phosphate groups produces a nucleotide. Without the
phosphate group, the molecule is a nucleoside, not a nucleotide.
5. Which pentose sugar is found in DNA?
A) Ribose
B) Deoxyribose
C) Fructose
D) Glucose
Correct Answer: Deoxyribose
Rationale: DNA contains 2-deoxyribose. The absence of the 2' hydroxyl group
distinguishes deoxyribose from ribose and contributes to important chemical
differences between DNA and RNA. Fructose and glucose are hexoses, not pentoses.
6. Which pentose sugar is characteristic of RNA?
A) Ribose
B) Deoxyribose
C) Galactose
D) Mannose
Correct Answer: Ribose
