Biochemistry: Concepts and Connections – Test Bank
(2nd Edition, Appling, Anthony-Cahill & Mathews) –
Complete Exam Questions
1) The water content in the human body is approximately:
A) 90%
B) 80%
C) 70%
D) 60%
E) 50%
Answer: C) 70%
Rationale: Water is the most abundant molecule in the
human body, accounting for approximately 70% of body
weight. This percentage varies based on factors like age,
sex, and body composition .
2) The four most abundant chemical elements in living
systems are:
A) Hydrogen, oxygen, sulfur and phosphorus.
1
,B) Hydrogen, carbon, nitrogen and oxygen.
C) Sodium, potassium, carbon and oxygen.
D) Sodium, potassium, nitrogen and sulfur.
E) Carbon, nitrogen, oxygen and potassium.
Answer: B) Hydrogen, carbon, nitrogen and oxygen.
Rationale: These four elements constitute roughly 96% of
the mass of living organisms. Carbon provides the
backbone for organic molecules, while hydrogen, oxygen,
and nitrogen are essential for functional groups and
water .
3) Nearly all proteins contain:
A) Cobalt
B) Phosphorus
C) Selenium
D) Sulfur
E) None of the above
Answer: D) Sulfur
Rationale: Sulfur is present in the amino acids methionine
2
,and cysteine. Disulfide bonds formed between cysteine
residues are crucial for stabilizing the three-dimensional
structure of many proteins .
4) Which of the following statements is FALSE?
A) Proteins can be structural components of cells.
B) Proteins can transmit signals between cells.
C) Proteins can transport molecules within cells and
between cells.
D) Proteins can be both hormones and hormone receptors.
E) Proteins are the only biological polymer that can
catalyze biochemical reactions.
Answer: E) Proteins are the only biological polymer that
can catalyze biochemical reactions.
Rationale: While proteins (enzymes) are the primary
catalysts, RNA molecules (ribozymes) can also catalyze
specific biochemical reactions, making this statement
false .
3
, 5) Which of the following is NOT classed as a lipid?
A) Cholesterol
B) Palmitic acid
C) Glycerol
D) Phosphatidyl serine
E) Triacylglycerol
Answer: C) Glycerol
Rationale: Glycerol is a three-carbon alcohol that forms
the backbone of many lipids (like triglycerides and
phospholipids), but it is not hydrophobic or amphipathic
on its own, and therefore is not classified as a lipid .
6) The chemical element ________ has a role in both
transfer of energy as well as in the structure of nucleic
acids.
A) Nitrogen
B) Sulfur
C) Phosphorus
4
(2nd Edition, Appling, Anthony-Cahill & Mathews) –
Complete Exam Questions
1) The water content in the human body is approximately:
A) 90%
B) 80%
C) 70%
D) 60%
E) 50%
Answer: C) 70%
Rationale: Water is the most abundant molecule in the
human body, accounting for approximately 70% of body
weight. This percentage varies based on factors like age,
sex, and body composition .
2) The four most abundant chemical elements in living
systems are:
A) Hydrogen, oxygen, sulfur and phosphorus.
1
,B) Hydrogen, carbon, nitrogen and oxygen.
C) Sodium, potassium, carbon and oxygen.
D) Sodium, potassium, nitrogen and sulfur.
E) Carbon, nitrogen, oxygen and potassium.
Answer: B) Hydrogen, carbon, nitrogen and oxygen.
Rationale: These four elements constitute roughly 96% of
the mass of living organisms. Carbon provides the
backbone for organic molecules, while hydrogen, oxygen,
and nitrogen are essential for functional groups and
water .
3) Nearly all proteins contain:
A) Cobalt
B) Phosphorus
C) Selenium
D) Sulfur
E) None of the above
Answer: D) Sulfur
Rationale: Sulfur is present in the amino acids methionine
2
,and cysteine. Disulfide bonds formed between cysteine
residues are crucial for stabilizing the three-dimensional
structure of many proteins .
4) Which of the following statements is FALSE?
A) Proteins can be structural components of cells.
B) Proteins can transmit signals between cells.
C) Proteins can transport molecules within cells and
between cells.
D) Proteins can be both hormones and hormone receptors.
E) Proteins are the only biological polymer that can
catalyze biochemical reactions.
Answer: E) Proteins are the only biological polymer that
can catalyze biochemical reactions.
Rationale: While proteins (enzymes) are the primary
catalysts, RNA molecules (ribozymes) can also catalyze
specific biochemical reactions, making this statement
false .
3
, 5) Which of the following is NOT classed as a lipid?
A) Cholesterol
B) Palmitic acid
C) Glycerol
D) Phosphatidyl serine
E) Triacylglycerol
Answer: C) Glycerol
Rationale: Glycerol is a three-carbon alcohol that forms
the backbone of many lipids (like triglycerides and
phospholipids), but it is not hydrophobic or amphipathic
on its own, and therefore is not classified as a lipid .
6) The chemical element ________ has a role in both
transfer of energy as well as in the structure of nucleic
acids.
A) Nitrogen
B) Sulfur
C) Phosphorus
4
