CHEM 210 Biochemistry Module 1 to 8
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026/2027 Q&A Grade A+
1. Which property of water allows it to stabilize temperature in
biological systems?
A. High polarity
B. High density
C. Low viscosity
D. High specific heat
Answer: D. High specific heat
Rationale: Hydrogen bonding allows water to absorb large amounts
of heat without drastic temperature change.
2. Hydrogen bonds are strongest when:
A. Atoms are far apart
B. Charges are equal
C. Atoms are linear and close
D. Electrons are shared
Answer: C. Atoms are linear and close
Rationale: Proper alignment maximizes electrostatic attraction in
hydrogen bonds.
3. A solution with a pH of 3 is:
A. Basic
B. Neutral
, C. Weakly basic
D. Acidic
Answer: D. Acidic
Rationale: Lower pH values indicate higher hydrogen ion
concentration.
4. Which amino acid is nonpolar?
A. Serine
B. Aspartate
C. Alanine
D. Lysine
Answer: C. Alanine
Rationale: Alanine has a nonpolar methyl side chain.
5. At physiological pH, amino acids usually exist as:
A. Negatively charged ions
B. Positively charged ions
C. Zwitterions
D. Neutral molecules
Answer: C. Zwitterions
Rationale: They contain both a positive amino group and a negative
carboxyl group.
6. Peptide bonds are formed by a reaction between:
A. Two amino groups
B. Two carboxyl groups
, C. Amino and carboxyl groups
D. Side chains
Answer: C. Amino and carboxyl groups
Rationale: A dehydration reaction links amino acids together.
7. Which level of protein structure involves alpha helices and beta
sheets?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
Answer: B. Secondary
Rationale: Hydrogen bonding between backbone atoms stabilizes
these structures.
8. The primary structure of a protein is defined by its:
A. Folding pattern
B. Biological function
C. Amino acid sequence
D. Disulfide bonds
Answer: C. Amino acid sequence
Rationale: This sequence determines all higher levels of structure.
9. Disulfide bonds form between which amino acids?
A. Methionine
B. Glycine
, C. Cysteine
D. Proline
Answer: C. Cysteine
Rationale: Cysteine contains sulfhydryl groups that form covalent
disulfide bonds.
10. Protein denaturation typically results in loss of:
A. Primary structure
B. Peptide bonds
C. Secondary and tertiary structure
D. Amino acid composition
Answer: C. Secondary and tertiary structure
Rationale: Denaturation disrupts noncovalent interactions, not
peptide bonds.
11. Enzymes increase reaction rates by:
A. Increasing ΔG
B. Lowering activation energy
C. Changing equilibrium
D. Adding energy to products
Answer: B. Lowering activation energy
Rationale: They stabilize the transition state without altering
thermodynamics.
12. The active site of an enzyme is the region that:
A. Binds cofactors only
B. Binds inhibitors only
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026/2027 Q&A Grade A+
1. Which property of water allows it to stabilize temperature in
biological systems?
A. High polarity
B. High density
C. Low viscosity
D. High specific heat
Answer: D. High specific heat
Rationale: Hydrogen bonding allows water to absorb large amounts
of heat without drastic temperature change.
2. Hydrogen bonds are strongest when:
A. Atoms are far apart
B. Charges are equal
C. Atoms are linear and close
D. Electrons are shared
Answer: C. Atoms are linear and close
Rationale: Proper alignment maximizes electrostatic attraction in
hydrogen bonds.
3. A solution with a pH of 3 is:
A. Basic
B. Neutral
, C. Weakly basic
D. Acidic
Answer: D. Acidic
Rationale: Lower pH values indicate higher hydrogen ion
concentration.
4. Which amino acid is nonpolar?
A. Serine
B. Aspartate
C. Alanine
D. Lysine
Answer: C. Alanine
Rationale: Alanine has a nonpolar methyl side chain.
5. At physiological pH, amino acids usually exist as:
A. Negatively charged ions
B. Positively charged ions
C. Zwitterions
D. Neutral molecules
Answer: C. Zwitterions
Rationale: They contain both a positive amino group and a negative
carboxyl group.
6. Peptide bonds are formed by a reaction between:
A. Two amino groups
B. Two carboxyl groups
, C. Amino and carboxyl groups
D. Side chains
Answer: C. Amino and carboxyl groups
Rationale: A dehydration reaction links amino acids together.
7. Which level of protein structure involves alpha helices and beta
sheets?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
Answer: B. Secondary
Rationale: Hydrogen bonding between backbone atoms stabilizes
these structures.
8. The primary structure of a protein is defined by its:
A. Folding pattern
B. Biological function
C. Amino acid sequence
D. Disulfide bonds
Answer: C. Amino acid sequence
Rationale: This sequence determines all higher levels of structure.
9. Disulfide bonds form between which amino acids?
A. Methionine
B. Glycine
, C. Cysteine
D. Proline
Answer: C. Cysteine
Rationale: Cysteine contains sulfhydryl groups that form covalent
disulfide bonds.
10. Protein denaturation typically results in loss of:
A. Primary structure
B. Peptide bonds
C. Secondary and tertiary structure
D. Amino acid composition
Answer: C. Secondary and tertiary structure
Rationale: Denaturation disrupts noncovalent interactions, not
peptide bonds.
11. Enzymes increase reaction rates by:
A. Increasing ΔG
B. Lowering activation energy
C. Changing equilibrium
D. Adding energy to products
Answer: B. Lowering activation energy
Rationale: They stabilize the transition state without altering
thermodynamics.
12. The active site of an enzyme is the region that:
A. Binds cofactors only
B. Binds inhibitors only
