BIOCHEMISTRY CHEM 210 EXAM PREP
TEST BANK 150 Practice Questions with
Verified Answers & Detailed Rationales
Latest 2026/2027 Edition | Portage
Learning | A+ Graded
SECTION I: Foundations of Biochemistry & Water Properties
(Questions 1-20)
1. What is biochemistry?
A. The study of inorganic compounds
B. The study of non-carbon compounds
C. The chemistry of life
D. The study of metals and minerals
Correct Answer: C
Rationale: Biochemistry is the branch of science that explores the chemical processes
within and related to living organisms .
2. What are the three primary ways that biochemists study biological organisms?
A. Structure-function relationships, metabolic reactions, and cellular
communication
B. Genetic inheritance, protein synthesis, and energy production
C. Cellular respiration, photosynthesis, and DNA replication
D. Enzyme regulation, hormone signaling, and immune response
,Correct Answer: A
Rationale: Biochemists study the relationship between structure and function of
biomolecules, the chemical reactions of organisms (metabolism), and communication
within and among organisms. These three pillars form the foundation of biochemical
inquiry .
3. Which element is considered critical to all living things and is found in large
amounts?
A. Oxygen
B. Nitrogen
C. Carbon
D. Hydrogen
Correct Answer: C
Rationale: Carbon is unique because it can form four stable covalent bonds, allowing it
to serve as the central building block for countless complex organic molecules and form
diverse structures including long chains, rings, and multiple bonds .
4. How many of the 90 naturally occurring elements are found in living organisms?
A. All 90
B. More than 50
C. Less than 30
D. Exactly 45
Correct Answer: C
Rationale: Fewer than 30 naturally occurring elements are essential to life. Smaller
elements (nonmetals in the upper right of the periodic table) are favored because they
form stable covalent bonds .
,5. Which of the following elements accounts for more than 97% of the weight of
most organisms?
A. C, H, O, N, Ca, Mg
B. C, H, O, N, P, S
C. C, H, N, O, K, Cl
D. C, H, O, N, Fe, Zn
Correct Answer: B
Rationale: Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (CHONPS)
account for more than 97% of the weight of most organisms. These are the primary
elements found in biomolecules such as proteins, nucleic acids, carbohydrates, and
lipids .
6. What property of carbon makes it uniquely suited as the backbone of biological
molecules?
A. Carbon has six valence electrons, allowing it to form six bonds
B. Carbon can form stable covalent bonds, long chains, double/triple bonds, and
ring structures
C. Carbon is the most abundant element in living organisms
D. Carbon forms only ionic bonds with other elements
Correct Answer: B
Rationale: Carbon has four valence electrons and forms stable covalent bonds, allowing
it to create long chains, double and triple bonds, and cyclic structures. This versatility
makes carbon the ideal element for the vast diversity of biological molecules .
7. What is the difference between organic and inorganic chemistry?
A. Organic studies salts, inorganic studies proteins
B. Organic studies metals, inorganic studies nonmetals
C. Organic is the study of carbon-based compounds, inorganic is the study of
, compounds not typically containing carbon
D. Organic is physics-based, inorganic is biology-based
Correct Answer: C
Rationale: Organic chemistry is the study of carbon-based compounds (with C-H
bonds), while inorganic chemistry is the study of compounds not typically containing
carbon, such as salts and minerals .
8. What is the bond angle associated with a tetrahedral molecular shape?
A. 90 degrees
B. 109.5 degrees
C. 120 degrees
D. 180 degrees
Correct Answer: B
Rationale: A tetrahedral molecule, such as methane (CH₄), has bond angles of
approximately 109.5°. This is the characteristic bond angle for sp³ hybridized carbon
atoms .
9. What is the approximate bond angle of water, and what is its molecular
geometry?
A. 109.5°, tetrahedral
B. 104.5°, bent
C. 120°, trigonal planar
D. 107.5°, trigonal pyramidal
Correct Answer: B
Rationale: Water has a bent molecular geometry with a bond angle of approximately
104.5°. This geometry arises from the two lone pairs of electrons on oxygen, which
compress the H-O-H bond angle from the ideal tetrahedral 109.5° .
TEST BANK 150 Practice Questions with
Verified Answers & Detailed Rationales
Latest 2026/2027 Edition | Portage
Learning | A+ Graded
SECTION I: Foundations of Biochemistry & Water Properties
(Questions 1-20)
1. What is biochemistry?
A. The study of inorganic compounds
B. The study of non-carbon compounds
C. The chemistry of life
D. The study of metals and minerals
Correct Answer: C
Rationale: Biochemistry is the branch of science that explores the chemical processes
within and related to living organisms .
2. What are the three primary ways that biochemists study biological organisms?
A. Structure-function relationships, metabolic reactions, and cellular
communication
B. Genetic inheritance, protein synthesis, and energy production
C. Cellular respiration, photosynthesis, and DNA replication
D. Enzyme regulation, hormone signaling, and immune response
,Correct Answer: A
Rationale: Biochemists study the relationship between structure and function of
biomolecules, the chemical reactions of organisms (metabolism), and communication
within and among organisms. These three pillars form the foundation of biochemical
inquiry .
3. Which element is considered critical to all living things and is found in large
amounts?
A. Oxygen
B. Nitrogen
C. Carbon
D. Hydrogen
Correct Answer: C
Rationale: Carbon is unique because it can form four stable covalent bonds, allowing it
to serve as the central building block for countless complex organic molecules and form
diverse structures including long chains, rings, and multiple bonds .
4. How many of the 90 naturally occurring elements are found in living organisms?
A. All 90
B. More than 50
C. Less than 30
D. Exactly 45
Correct Answer: C
Rationale: Fewer than 30 naturally occurring elements are essential to life. Smaller
elements (nonmetals in the upper right of the periodic table) are favored because they
form stable covalent bonds .
,5. Which of the following elements accounts for more than 97% of the weight of
most organisms?
A. C, H, O, N, Ca, Mg
B. C, H, O, N, P, S
C. C, H, N, O, K, Cl
D. C, H, O, N, Fe, Zn
Correct Answer: B
Rationale: Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (CHONPS)
account for more than 97% of the weight of most organisms. These are the primary
elements found in biomolecules such as proteins, nucleic acids, carbohydrates, and
lipids .
6. What property of carbon makes it uniquely suited as the backbone of biological
molecules?
A. Carbon has six valence electrons, allowing it to form six bonds
B. Carbon can form stable covalent bonds, long chains, double/triple bonds, and
ring structures
C. Carbon is the most abundant element in living organisms
D. Carbon forms only ionic bonds with other elements
Correct Answer: B
Rationale: Carbon has four valence electrons and forms stable covalent bonds, allowing
it to create long chains, double and triple bonds, and cyclic structures. This versatility
makes carbon the ideal element for the vast diversity of biological molecules .
7. What is the difference between organic and inorganic chemistry?
A. Organic studies salts, inorganic studies proteins
B. Organic studies metals, inorganic studies nonmetals
C. Organic is the study of carbon-based compounds, inorganic is the study of
, compounds not typically containing carbon
D. Organic is physics-based, inorganic is biology-based
Correct Answer: C
Rationale: Organic chemistry is the study of carbon-based compounds (with C-H
bonds), while inorganic chemistry is the study of compounds not typically containing
carbon, such as salts and minerals .
8. What is the bond angle associated with a tetrahedral molecular shape?
A. 90 degrees
B. 109.5 degrees
C. 120 degrees
D. 180 degrees
Correct Answer: B
Rationale: A tetrahedral molecule, such as methane (CH₄), has bond angles of
approximately 109.5°. This is the characteristic bond angle for sp³ hybridized carbon
atoms .
9. What is the approximate bond angle of water, and what is its molecular
geometry?
A. 109.5°, tetrahedral
B. 104.5°, bent
C. 120°, trigonal planar
D. 107.5°, trigonal pyramidal
Correct Answer: B
Rationale: Water has a bent molecular geometry with a bond angle of approximately
104.5°. This geometry arises from the two lone pairs of electrons on oxygen, which
compress the H-O-H bond angle from the ideal tetrahedral 109.5° .
