1 | Page
PORTAGE LEARNING CHEM 210 BIOCHEMISTRY EXAM PACK
(MODULES 1–8) | 140 VERIFIED QUESTIONS WITH ANSWERS &
RATIONALES | 100% STUDY SUCCESS
1.
Biochemistry identifies four fundamental types of biomolecules that are essential
to all living organisms and their functions.
Which combination correctly lists these four classes?
A. Proteins, nucleic acids, lipids, and carbohydrates
B. Sugars, fats, water, and oxygen
C. Amino acids, enzymes, ATP, and glucose
D. Vitamins, minerals, lipids, and fibers
Correct Answer: A
Rationale: The four biomolecule classes—proteins, nucleic acids, lipids, and
carbohydrates—serve as the major macromolecules responsible for structure,
storage, communication, and metabolism in living organisms.
2.
DNA’s double-helix structure is held together by specific interactions between
nitrogenous bases.
Which type of bond connects these base pairs?
A. Ionic bonds
B. Covalent bonds
C. Hydrogen bonds
D. Peptide bonds
Correct Answer: C
Rationale: Weak hydrogen bonds form between complementary bases (A–T and
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G–C), allowing the DNA double helix to remain stable yet capable of unzipping
for replication.
3.
Proteins are large biomolecules built from smaller repeating units.
What are the building blocks of proteins?
A. Fatty acids
B. Monosaccharides
C. Amino acids
D. Nucleotides
Correct Answer: C
Rationale: Amino acids link together through peptide bonds to form proteins,
which act as enzymes, hormones, and structural components in cells.
4.
Enzymes accelerate biochemical reactions by influencing a specific energy barrier.
What do enzymes primarily do to speed up reactions?
A. Increase activation energy
B. Lower activation energy
C. Convert reactants into products directly
D. Change the reaction equilibrium
Correct Answer: B
Rationale: Enzymes lower the activation energy needed for a reaction, allowing
biological processes to proceed rapidly under mild conditions.
5.
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Protein structure has multiple levels of organization.
Which level is determined by hydrogen bonding between atoms of the peptide
backbone?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Correct Answer: B
Rationale: The secondary structure involves hydrogen bonds forming α-helices
and β-sheets that stabilize the protein’s shape.
6.
Energy transfer in biological systems depends on a high-energy molecule.
Which molecule serves as the cell’s main energy currency?
A. NADH
B. FADH₂
C. ATP
D. ADP
Correct Answer: C
Rationale: ATP (adenosine triphosphate) stores chemical energy in its phosphate
bonds and releases it to power cellular work.
7.
The breakdown of glucose into two molecules of pyruvate is an essential metabolic
pathway.
What is this process called?
A. Glycolysis
B. Fermentation
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C. Gluconeogenesis
D. Citric acid cycle
Correct Answer: A
Rationale: Glycolysis occurs in the cytoplasm, converting glucose into pyruvate
and generating a net gain of two ATP molecules.
8.
During aerobic respiration, the citric acid cycle occurs in a specific cellular
location.
Where does this process take place?
A. Cytoplasm
B. Nucleus
C. Mitochondrial matrix
D. Endoplasmic reticulum
Correct Answer: C
Rationale: The citric acid cycle (Krebs cycle) takes place in the mitochondrial
matrix, producing NADH and FADH₂ for oxidative phosphorylation.
9.
In cellular respiration, the majority of ATP is generated through one key process.
Which process produces the most ATP molecules?
A. Glycolysis
B. Fermentation
C. Electron transport chain
D. Krebs cycle
Correct Answer: C
Rationale: The electron transport chain uses oxygen as the final electron acceptor,
generating most ATP through oxidative phosphorylation.
PORTAGE LEARNING CHEM 210 BIOCHEMISTRY EXAM PACK
(MODULES 1–8) | 140 VERIFIED QUESTIONS WITH ANSWERS &
RATIONALES | 100% STUDY SUCCESS
1.
Biochemistry identifies four fundamental types of biomolecules that are essential
to all living organisms and their functions.
Which combination correctly lists these four classes?
A. Proteins, nucleic acids, lipids, and carbohydrates
B. Sugars, fats, water, and oxygen
C. Amino acids, enzymes, ATP, and glucose
D. Vitamins, minerals, lipids, and fibers
Correct Answer: A
Rationale: The four biomolecule classes—proteins, nucleic acids, lipids, and
carbohydrates—serve as the major macromolecules responsible for structure,
storage, communication, and metabolism in living organisms.
2.
DNA’s double-helix structure is held together by specific interactions between
nitrogenous bases.
Which type of bond connects these base pairs?
A. Ionic bonds
B. Covalent bonds
C. Hydrogen bonds
D. Peptide bonds
Correct Answer: C
Rationale: Weak hydrogen bonds form between complementary bases (A–T and
,2 | Page
G–C), allowing the DNA double helix to remain stable yet capable of unzipping
for replication.
3.
Proteins are large biomolecules built from smaller repeating units.
What are the building blocks of proteins?
A. Fatty acids
B. Monosaccharides
C. Amino acids
D. Nucleotides
Correct Answer: C
Rationale: Amino acids link together through peptide bonds to form proteins,
which act as enzymes, hormones, and structural components in cells.
4.
Enzymes accelerate biochemical reactions by influencing a specific energy barrier.
What do enzymes primarily do to speed up reactions?
A. Increase activation energy
B. Lower activation energy
C. Convert reactants into products directly
D. Change the reaction equilibrium
Correct Answer: B
Rationale: Enzymes lower the activation energy needed for a reaction, allowing
biological processes to proceed rapidly under mild conditions.
5.
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Protein structure has multiple levels of organization.
Which level is determined by hydrogen bonding between atoms of the peptide
backbone?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Correct Answer: B
Rationale: The secondary structure involves hydrogen bonds forming α-helices
and β-sheets that stabilize the protein’s shape.
6.
Energy transfer in biological systems depends on a high-energy molecule.
Which molecule serves as the cell’s main energy currency?
A. NADH
B. FADH₂
C. ATP
D. ADP
Correct Answer: C
Rationale: ATP (adenosine triphosphate) stores chemical energy in its phosphate
bonds and releases it to power cellular work.
7.
The breakdown of glucose into two molecules of pyruvate is an essential metabolic
pathway.
What is this process called?
A. Glycolysis
B. Fermentation
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C. Gluconeogenesis
D. Citric acid cycle
Correct Answer: A
Rationale: Glycolysis occurs in the cytoplasm, converting glucose into pyruvate
and generating a net gain of two ATP molecules.
8.
During aerobic respiration, the citric acid cycle occurs in a specific cellular
location.
Where does this process take place?
A. Cytoplasm
B. Nucleus
C. Mitochondrial matrix
D. Endoplasmic reticulum
Correct Answer: C
Rationale: The citric acid cycle (Krebs cycle) takes place in the mitochondrial
matrix, producing NADH and FADH₂ for oxidative phosphorylation.
9.
In cellular respiration, the majority of ATP is generated through one key process.
Which process produces the most ATP molecules?
A. Glycolysis
B. Fermentation
C. Electron transport chain
D. Krebs cycle
Correct Answer: C
Rationale: The electron transport chain uses oxygen as the final electron acceptor,
generating most ATP through oxidative phosphorylation.
