MOLECULAR BIOLOGY
& BIOCHEMISTRY
Biological Molecules
2026-2027 Academic Year
Verified Examination Questions with Answer Key
Q&A; | Instant Download PDF
EXAM SPECIFICATIONS
Time Allocation: 3 Hours
Total Questions: 100 Questions
Question Format: Multiple Choice with Rationales
Minimum Competency: 70% Required to Pass
Core Focus: Proteins, Nucleic Acids, Carbohydrates, Lipids, Enzymes
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 1
, Exam Overview & Content Outline
EXAM PURPOSE
Molecular Biology and Biochemistry – Biological Molecules covers structure, function, and
interactions of macromolecules: proteins, nucleic acids, carbohydrates, and lipids. Based on
university-level curriculum for 2026/2027 academic year aligned with ACS, ASBMB, and MCAT
standards.
CONTENT DISTRIBUTION
• Proteins & Amino Acids (30%) — Structure, folding, function, enzymes, kinetics, regulation
• Nucleic Acids (25%) — DNA/RNA structure, replication, transcription, translation, regulation
• Carbohydrates (20%) — Monosaccharides, polysaccharides, glycolysis, gluconeogenesis,
glycogen metabolism
• Lipids & Membranes (15%) — Fatty acids, phospholipids, membranes, transport, beta-oxidation,
cholesterol
• Metabolism & Bioenergetics (10%) — ATP, enzyme kinetics, metabolic pathways, regulation,
integration
QUESTION FORMAT & SCORING
Each item presents four options. Correct answers are highlighted in green with checkmark (✓).
Every question includes detailed rationale with biochemical principles. University standard requires
70% to pass.
STUDY STRATEGY
Master amino acid structures and protein folding. Know DNA/RNA structure and central dogma.
Understand enzyme kinetics: Km, Vmax, inhibition. Review carbohydrate metabolism pathways.
Study lipid structure and membrane function. Practice metabolism integration and regulation.
CURRICULUM ALIGNMENT
Questions reflect 2026-2027 standards: Lehninger Principles of Biochemistry, Alberts Molecular
Biology of the Cell, ACS Biochemistry Exam, ASBMB, and MCAT Biological and Biochemical
Foundations.
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 2
, SECTION I: Proteins & Amino Acids
1. Number of standard amino acids:
A. 10
✓ B. 20
C. 64
D. 4
Rationale: 20 standard amino acids encoded by genetic code. Essential: 9 cannot be synthesized (His, Ile,
Leu, Lys, Met, Phe, Thr, Trp, Val). Nonessential: 11 synthesized. Each has α-carbon, amino group, carboxyl
group, R-group, hydrogen. R-groups determine properties: nonpolar, polar, acidic, basic.
2. Peptide bond formation:
A. Hydrolysis reaction
✓ B. Condensation/dehydration between amino and carboxyl groups
C. Ionic bond
D. Hydrogen bond
Rationale: Peptide bond: Condensation reaction between α-carboxyl of one amino acid and α-amino of next.
Releases H2O. Forms planar, rigid bond with partial double-bond character, no rotation. N-Cα and Cα-C
bonds rotate. Polypeptide: N-terminus to C-terminus. Cleaved by proteases.
3. α-helix stabilized by:
A. Ionic bonds
✓ B. Hydrogen bonds between CO and NH groups 4 residues apart
C. Disulfide bonds
D. Hydrophobic interactions only
Rationale: α-helix: Secondary structure, right-handed, 3.6 residues/turn. Stabilized by H-bonds between CO
of residue n and NH of residue n+4. R-groups point outward. Proline breaks helix. Amphipathic helices
common in membranes. Common in globular proteins like myoglobin.
4. β-sheet structure:
A. Helical only
✓ B. Extended strands H-bonded, parallel or antiparallel
C. No structure
D. Circular
Rationale: β-sheet: Secondary structure, extended polypeptide strands. Antiparallel: strands run opposite
directions, H-bonds linear, more stable. Parallel: same direction, H-bonds angled. R-groups alternate
above/below sheet. Found in silk fibroin, immunoglobulins. Can form β-barrels.
5. Tertiary structure stabilized by:
A. Peptide bonds only
✓ B. Hydrophobic interactions, H-bonds, ionic bonds, disulfide bonds
C. Glycosidic bonds
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 3
& BIOCHEMISTRY
Biological Molecules
2026-2027 Academic Year
Verified Examination Questions with Answer Key
Q&A; | Instant Download PDF
EXAM SPECIFICATIONS
Time Allocation: 3 Hours
Total Questions: 100 Questions
Question Format: Multiple Choice with Rationales
Minimum Competency: 70% Required to Pass
Core Focus: Proteins, Nucleic Acids, Carbohydrates, Lipids, Enzymes
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 1
, Exam Overview & Content Outline
EXAM PURPOSE
Molecular Biology and Biochemistry – Biological Molecules covers structure, function, and
interactions of macromolecules: proteins, nucleic acids, carbohydrates, and lipids. Based on
university-level curriculum for 2026/2027 academic year aligned with ACS, ASBMB, and MCAT
standards.
CONTENT DISTRIBUTION
• Proteins & Amino Acids (30%) — Structure, folding, function, enzymes, kinetics, regulation
• Nucleic Acids (25%) — DNA/RNA structure, replication, transcription, translation, regulation
• Carbohydrates (20%) — Monosaccharides, polysaccharides, glycolysis, gluconeogenesis,
glycogen metabolism
• Lipids & Membranes (15%) — Fatty acids, phospholipids, membranes, transport, beta-oxidation,
cholesterol
• Metabolism & Bioenergetics (10%) — ATP, enzyme kinetics, metabolic pathways, regulation,
integration
QUESTION FORMAT & SCORING
Each item presents four options. Correct answers are highlighted in green with checkmark (✓).
Every question includes detailed rationale with biochemical principles. University standard requires
70% to pass.
STUDY STRATEGY
Master amino acid structures and protein folding. Know DNA/RNA structure and central dogma.
Understand enzyme kinetics: Km, Vmax, inhibition. Review carbohydrate metabolism pathways.
Study lipid structure and membrane function. Practice metabolism integration and regulation.
CURRICULUM ALIGNMENT
Questions reflect 2026-2027 standards: Lehninger Principles of Biochemistry, Alberts Molecular
Biology of the Cell, ACS Biochemistry Exam, ASBMB, and MCAT Biological and Biochemical
Foundations.
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 2
, SECTION I: Proteins & Amino Acids
1. Number of standard amino acids:
A. 10
✓ B. 20
C. 64
D. 4
Rationale: 20 standard amino acids encoded by genetic code. Essential: 9 cannot be synthesized (His, Ile,
Leu, Lys, Met, Phe, Thr, Trp, Val). Nonessential: 11 synthesized. Each has α-carbon, amino group, carboxyl
group, R-group, hydrogen. R-groups determine properties: nonpolar, polar, acidic, basic.
2. Peptide bond formation:
A. Hydrolysis reaction
✓ B. Condensation/dehydration between amino and carboxyl groups
C. Ionic bond
D. Hydrogen bond
Rationale: Peptide bond: Condensation reaction between α-carboxyl of one amino acid and α-amino of next.
Releases H2O. Forms planar, rigid bond with partial double-bond character, no rotation. N-Cα and Cα-C
bonds rotate. Polypeptide: N-terminus to C-terminus. Cleaved by proteases.
3. α-helix stabilized by:
A. Ionic bonds
✓ B. Hydrogen bonds between CO and NH groups 4 residues apart
C. Disulfide bonds
D. Hydrophobic interactions only
Rationale: α-helix: Secondary structure, right-handed, 3.6 residues/turn. Stabilized by H-bonds between CO
of residue n and NH of residue n+4. R-groups point outward. Proline breaks helix. Amphipathic helices
common in membranes. Common in globular proteins like myoglobin.
4. β-sheet structure:
A. Helical only
✓ B. Extended strands H-bonded, parallel or antiparallel
C. No structure
D. Circular
Rationale: β-sheet: Secondary structure, extended polypeptide strands. Antiparallel: strands run opposite
directions, H-bonds linear, more stable. Parallel: same direction, H-bonds angled. R-groups alternate
above/below sheet. Found in silk fibroin, immunoglobulins. Can form β-barrels.
5. Tertiary structure stabilized by:
A. Peptide bonds only
✓ B. Hydrophobic interactions, H-bonds, ionic bonds, disulfide bonds
C. Glycosidic bonds
Molecular Biology & Biochemistry - Biological Molecules 2026-2027 Page 3
