Biomolecular Interactions – MCQs 50 Score: 0 Attempted: 0/50 Subscribe 1. Biomolecular interactions refer to: (A) Chemical reactions in rocks (B) Forces and bindings between biological macromolecules (C) Movement of planets (D) Heat transfer in metals 2. The primary interaction stabilizing DNA double helix is: (A) Ionic bonds (B) Hydrogen bonds between bases (C) Metallic bonds (D) Van der Waals forces 3. Stacking interactions between DNA bases are: (A) Hydrophobic and van der Waals interactions (B) Hydrogen bonding (C) Ionic bonds (D) Peptide bonds 4. Protein–protein interactions often involve: (A) Hydrogen bonds and hydrophobic patches (B) Only covalent bonds (C) Metallic bonds (D) Radioactive decay 5. The interaction between antigen and antibody is mainly: (A) Non-covalent interactions (B) Metallic bonding (C) Ionic lattices (D) Covalent peptide bonds 6. Which force drives protein folding? (A) Hydrophobic effect (B) Ionic repulsion (C) Metallic bonds (D) Nuclear forces 7. Van der Waals interactions are: (A) Strong covalent bonds (B) Weak, distance-dependent forces (C) Permanent ionic bonds (D) Only found in metals 8. Hydrogen bonds are stronger than: (A) Covalent bonds (B) Van der Waals forces (C) Ionic bonds (D) Peptide bonds 9. Salt bridges in proteins are formed by: (A) Ionic interactions between charged side chains (B) Covalent bonds between sulfur atoms (C) Van der Waals forces (D) Hydrophobic clustering 10. Enzyme–substrate binding is often explained by: (A) Lock and key or induced fit model (B) Covalent lattice model (C) Random force model (D) Peptide chain extension 11. The dissociation constant (Kd) measures: (A) Binding affinity between molecules (B) Rate of protein folding (C) Heat released in reactions (D) Size of DNA helix 12. A low Kd value indicates: (A) Weak binding (B) Strong binding (C) No binding (D) Random binding 13. Hydrophobic interactions are stronger in: (A) Non-polar environments (B) Polar solvents like water (C) Metallic lattices (D) Vacuum 14. Which amino acids often form hydrogen bonds? (A) Polar side chain amino acids (B) Non-polar side chain amino acids (C) Hydrophobic residues only (D) Sulfur atoms only 15. Disulfide bonds in proteins are: (A) Covalent bonds between cysteine residues (B) Ionic bonds between lysine and glutamate (C) Van der Waals contacts (D) Hydrogen bonds 16. Protein–DNA binding is often mediated by: (A) Electrostatic and hydrogen bonding (B) Metallic bonds (C) Only van der Waals forces (D) Radioactive decay 17. Transcription factors recognize DNA through: (A) Major and minor grooves (B) Covalent attachments (C) Random diffusion only (D) Base-pair substitution 18. Which biomolecular interaction is reversible? (A) Hydrogen bonding (B) Ionic bonding in water (C) Van der Waals interactions (D) All of the above 19. Ligand–receptor interactions are often studied by: (A) Surface plasmon resonance (SPR) (B) X-ray crystallography only (C) Metal conductivity tests (D) Thermal fusion 20. Hydrophobic effect leads to: (A) Clustering of nonpolar molecules in aqueous environments (B) Dissolution of proteins in water (C) Ionic bond formation (D) Protein denaturation only 21. Cooperative binding is best exemplified by: (A) Hemoglobin binding to oxygen (B) Enzyme catalysis (C) Antibody-antigen recognition (D) Lipid bilayer formation 22. The Hill coefficient measures: (A) Degree of cooperativity in binding (B) Rate of enzyme folding (C) DNA melting temperature (D) Protein denaturation energy 23. A Hill coefficient greater than 1 indicates: (A) Negative cooperativity (B) Positive cooperativity (C) No cooperativity (D) Random binding 24. Molecular docking is a technique to: (A) Predict binding between molecules (B) Measure protein mass (C) Visualize DNA (D) Quantify cell division 25. Protein–lipid interactions are critical for: (A) Membrane structure and function (B) DNA replication (C) Muscle contraction only (D) Bone strength 26. The main driving force for micelle formation is: (A) Hydrophobic effect (B) Hydrogen bonding (C) Ionic strength (D) Disulfide linkage 27. Electrostatic interactions are weakened by: (A) High salt concentration (B) Vacuum (C) Temperature stability (D) Disulfide bonding 28. Hydrogen bonds in water are approximately: (A) 1–5 kcal/mol (B) 20–30 kcal/mol (C) 50–60 kcal/mol 29. Protein aggregation is often caused by: (A) Hydrophobic interactions (B) Strong covalent bonding (C) DNA interference (D) Ionic shielding only 30. π–π interactions occur between: (A) Aromatic rings (B) Aliphatic chains (C) Ionic salts (D) Disulfide bonds 31. Ligand binding to enzymes often alters: (A) Protein conformation (B) DNA sequence (C) RNA transcription rate directly (D) Atomic number 32. The binding free energy (ΔG) of interactions is related to: (A) Kd (dissociation constant) (B) Young’s modulus (C) Poisson’s ratio (D) Pressure-volume work only 33. The main structural forces in collagen are: (A) Hydrogen bonds and covalent cross-links (B) Ionic lattices (C) Metallic bonds (D) Magnetic dipoles 34. In protein folding, chaperones prevent: (A) Misfolding and aggregation (B) ATP synthesis (C) DNA replication (D) Ion transport 35. Specificity of enzyme–substrate interaction arises from: (A) Complementary shape and chemical properties (B) Random binding (C) Heat transfer (D) Electrostatic shielding only 36. DNA melting temperature (Tm) increases with: (A) Higher GC content (B) Higher AT content (C) More hydrogen bond disruption (D) Presence of mutations 37. Protein–RNA interactions are critical for: (A) Translation and splicing (B) DNA replication only (C) Carbohydrate metabolism (D) Lipid synthesis only 38. Which is the strongest type of biomolecular interaction? (A) Covalent bonds (B) Ionic bonds (C) Hydrogen bonds (D) Van der Waals interactions 39. The molecular recognition process is guided by: (A) Shape complementarity and weak forces (B) Random collisions only (C) DNA sequencing (D) Protein aggregation 40. An example of allosteric regulation is: (A) Oxygen binding to hemoglobin (B) ATP hydrolysis (C) DNA replication (D) RNA transcription 41. The Bohr effect describes: (A) Effect of pH on oxygen binding to hemoglobin (B) Effect of heat on protein folding (C) Protein aggregation in cells (D) DNA base stacking 42. Cooperative ligand binding leads to: (A) Sigmoidal binding curve (B) Linear binding curve (C) Random fluctuations (D) Complete denaturation 43. Molecular crowding in cells affects: (A) Biomolecular interactions and reaction rates (B) Only protein denaturation (C) Only DNA replication (D) Only lipid folding 44. Solvent dielectric constant influences: (A) Electrostatic interactions (B) Peptide bond formation (C) Protein synthesis rate (D) Atomic mass 45. Ligand–receptor specificity is mainly due to: (A) Complementary shape and charge distribution (B) Random mutations (C) Ionic strength only (D) DNA polymerase activity 46. Cooperative protein unfolding transitions are studied using: (A) Differential scanning calorimetry (B) X-ray diffraction only (C) MRI imaging (D) Thermal conduction tests 47. π–cation interactions occur between: (A) Aromatic rings and positively charged groups (B) Ionic salts only (C) Covalent disulfide bonds (D) Metal lattices 48. Enthalpic contributions in binding come from: (A) Hydrogen bonding, electrostatics, van der Waals (B) Random diffusion (C) Pressure-volume work only (D) Heat capacity 49. Entropic contributions in binding come from: (A) Solvent reorganization and conformational freedom (B) Heat conduction only (C) DNA mutation (D) Elastic forces 50. Biomolecular interactions are essential for: (A) Signal transduction, catalysis, recognition, and stability (B) Planetary motion (C) Rock formation (D) Nuclear fission Molecular Biophysics – MCQsCellular Biophysics – MCQsMembrane Biophysics – MCQsNeurobiophysics – MCQsRadiation Biophysics – MCQsMedical Biophysics – MCQsComputational Biophysics – MCQsStructural Biophysics – MCQsBiophysical Chemistry – MCQsBioenergetics – MCQsBiomechanics – MCQsSystems Biophysics – MCQsBiomolecular Interactions – MCQsBiophysical Methods & Instrumentation – MCQsQuantum Biophysics – MCQsThermodynamics & Statistical Mechanics in Biology – MCQsBiophysics of Macromolecules – MCQs Electrophysiology – MCQsPhotobiophysics – MCQsNanobiophysics – MCQs