CHEM 210 Module 1 Exam - Biochemistry Foundations Geneva College
1. Which of the following properties of water allows it to dissolve polar and
ionic substances effectively?
A. High surface tension
B. Density at 4 degrees Celsius
C. Low boiling point
D. High dielectric constant
Answer: D
Rationale: The high dielectric constant of water reduces the electrostatic forces between
ions, allowing it to dissolve salts and polar molecules.
2. Which of the following is the definition of pH?
A. The log of the hydrogen ion concentration
B. The negative log of the hydrogen ion concentration
C. The negative log of the hydroxide ion concentration
D. The natural log of the pKa
Answer: B
Rationale: pH is defined as the negative logarithm (base 10) of the molar concentration of
hydrogen ions [H+].
3. Which amino acid does not possess a chiral center?
A. Alanine
B. Proline
C. Glycine
D. Valine
Answer: C
,Rationale: Glycine’s R-group is a hydrogen atom, making it the only achiral amino acid
among the 20 standard amino acids.
4. What is the primary function of the mitochondria in a eukaryotic cell?
A. Protein synthesis
B. ATP production
C. Waste disposal
D. Lipid storage
Answer: B
Rationale: Mitochondria are the powerhouses of the cell, responsible for generating
adenosine triphosphate (ATP) through oxidative phosphorylation.
5. According to the Henderson-Hasselbalch equation, what happens when pH =
pKa?
A. The concentration of acid is zero
B. The concentration of base is zero
C. The solution is at pH 7
D. The concentration of acid equals the concentration of conjugate base
Answer: D
Rationale: In the equation pH = pKa + log([A-]/[HA]), if [A-] = [HA], the log of 1 is 0, so pH
= pKa.
6. Which of the following amino acids is classified as basic?
A. Aspartate
B. Lysine
C. Leucine
D. Serine
Answer: B
Rationale: Lysine, Arginine, and Histidine have positively charged side chains at
physiological pH and are classified as basic amino acids.
, 7. What type of bond is formed between the carboxyl group of one amino acid
and the amino group of another?
A. Hydrogen bond
B. Ionic bond
C. Peptide bond
D. Glycosidic bond
Answer: C
Rationale: Amino acids are linked by peptide bonds, which are covalent amide bonds
formed via a dehydration reaction.
8. The hydrophobic effect is driven by an increase in which thermodynamic
property?
A. Entropy
B. Enthalpy
C. Free energy
D. Activation energy
Answer: A
Rationale: The hydrophobic effect is driven by an increase in the entropy of surrounding
water molecules as they are excluded from nonpolar surfaces.
9. Which organelle is responsible for the modification and sorting of proteins?
A. Ribosome
B. Golgi apparatus
C. Nucleus
D. Lysosome
Answer: B
Rationale: The Golgi apparatus modifies, sorts, and packages proteins for secretion or
delivery to other organelles.
1. Which of the following properties of water allows it to dissolve polar and
ionic substances effectively?
A. High surface tension
B. Density at 4 degrees Celsius
C. Low boiling point
D. High dielectric constant
Answer: D
Rationale: The high dielectric constant of water reduces the electrostatic forces between
ions, allowing it to dissolve salts and polar molecules.
2. Which of the following is the definition of pH?
A. The log of the hydrogen ion concentration
B. The negative log of the hydrogen ion concentration
C. The negative log of the hydroxide ion concentration
D. The natural log of the pKa
Answer: B
Rationale: pH is defined as the negative logarithm (base 10) of the molar concentration of
hydrogen ions [H+].
3. Which amino acid does not possess a chiral center?
A. Alanine
B. Proline
C. Glycine
D. Valine
Answer: C
,Rationale: Glycine’s R-group is a hydrogen atom, making it the only achiral amino acid
among the 20 standard amino acids.
4. What is the primary function of the mitochondria in a eukaryotic cell?
A. Protein synthesis
B. ATP production
C. Waste disposal
D. Lipid storage
Answer: B
Rationale: Mitochondria are the powerhouses of the cell, responsible for generating
adenosine triphosphate (ATP) through oxidative phosphorylation.
5. According to the Henderson-Hasselbalch equation, what happens when pH =
pKa?
A. The concentration of acid is zero
B. The concentration of base is zero
C. The solution is at pH 7
D. The concentration of acid equals the concentration of conjugate base
Answer: D
Rationale: In the equation pH = pKa + log([A-]/[HA]), if [A-] = [HA], the log of 1 is 0, so pH
= pKa.
6. Which of the following amino acids is classified as basic?
A. Aspartate
B. Lysine
C. Leucine
D. Serine
Answer: B
Rationale: Lysine, Arginine, and Histidine have positively charged side chains at
physiological pH and are classified as basic amino acids.
, 7. What type of bond is formed between the carboxyl group of one amino acid
and the amino group of another?
A. Hydrogen bond
B. Ionic bond
C. Peptide bond
D. Glycosidic bond
Answer: C
Rationale: Amino acids are linked by peptide bonds, which are covalent amide bonds
formed via a dehydration reaction.
8. The hydrophobic effect is driven by an increase in which thermodynamic
property?
A. Entropy
B. Enthalpy
C. Free energy
D. Activation energy
Answer: A
Rationale: The hydrophobic effect is driven by an increase in the entropy of surrounding
water molecules as they are excluded from nonpolar surfaces.
9. Which organelle is responsible for the modification and sorting of proteins?
A. Ribosome
B. Golgi apparatus
C. Nucleus
D. Lysosome
Answer: B
Rationale: The Golgi apparatus modifies, sorts, and packages proteins for secretion or
delivery to other organelles.
