Molecular Biophysics β MCQs 50 Score: 0 Attempted: 0/50 Subscribe 1. The primary structure of a protein is determined by: (A) Hydrogen bonds (B) Peptide bond sequence (C) Ionic interactions (D) Hydrophobic interactions 2. The alpha-helix is stabilized mainly by: (A) Disulfide bonds (B) Hydrogen bonds (C) Ionic bonds (D) Van der Waals forces 3. The diameter of the DNA double helix is approximately: (A) 1 nm (B) 2 nm (C) 5 nm (D) 10 nm 4. The secondary structure of proteins includes: (A) Alpha-helices and beta-sheets (B) Disulfide bridges (C) Quaternary assembly (D) Peptide bond sequence 5. Which technique is most commonly used to determine protein 3D structures? (A) UV spectroscopy (B) X-ray crystallography (C) SDS-PAGE (D) Light microscopy 6. Circular dichroism spectroscopy is primarily used to study: (A) Protein folding and secondary structure (B) DNA sequencing (C) Enzyme kinetics (D) Mutation analysis 7. In DNA, adenine pairs with: (A) Cytosine (B) Guanine (C) Thymine (D) Uracil 8. The quaternary structure of a protein refers to: (A) Sequence of amino acids (B) Hydrogen bonding patterns (C) Arrangement of multiple polypeptides (D) Folding into helices 9. The unit of molecular mass commonly used in biophysics is: (A) Dalton (B) Joule (C) Newton (D) Mole 10. Fluorescence spectroscopy in biophysics often exploits which amino acid? (A) Glycine (B) Tryptophan (C) Alanine (D) Valine 11. The B-form of DNA has how many base pairs per helical turn? (A) 8 (B) 10 (C) 12 (D) 14 12. Which bond connects nucleotides in DNA? (A) Peptide bond (B) Glycosidic bond (C) Phosphodiester bond (D) Hydrogen bond 13. Which technique is commonly used to study large biomolecular complexes in solution? (A) NMR spectroscopy (B) Electron microscopy (C) Raman spectroscopy (D) IR spectroscopy 14. The melting temperature (Tm) of DNA refers to the point at which: (A) Proteins denature (B) DNA strands separate (C) Peptide bonds break (D) ATP hydrolyzes 15. Which interaction primarily stabilizes beta-sheets? (A) Disulfide bonds (B) Hydrogen bonds (C) Covalent bonds (D) Ionic bonds 16. Molecular dynamics simulations provide: (A) Experimental protein structure (B) Computational motion of molecules over time (C) Only bond lengths (D) Mutation detection 17. Protein folding is mainly driven by: (A) Hydrophobic interactions (B) Ionic bonding (C) Disulfide cross-links (D) Hydrogen bonding only 18. The backbone of proteins is composed of repeating: (A) Sugar-phosphate units (B) Amino acid residues (C) Nucleotides (D) Fatty acids 19. ATP mainly stores energy in: (A) Adenine base (B) Ribose sugar (C) Phosphoanhydride bonds (D) Hydrogen bonds 20. Which spectroscopy technique is most suitable for studying protein-ligand interactions in real time? (A) UV-Vis (B) Surface plasmon resonance (SPR) (C) X-ray crystallography (D) Cryo-EM 21. Ramachandran plots are used to analyze: (A) DNA base-pairing (B) RNA transcription (C) Protein backbone conformations (D) Carbohydrate bonds 22. Which force stabilizes the DNA double helix? (A) Peptide bonds (B) Hydrogen bonds and base stacking (C) Covalent bonds (D) Ionic forces only 23. The primary function of molecular chaperones is to: (A) Replicate DNA (B) Help proteins fold correctly (C) Store energy (D) Break down ATP 24. Which method can measure the size distribution of proteins in solution? (A) Gel electrophoresis (B) Dynamic light scattering (C) PCR (D) Atomic absorption spectroscopy 25. The Z-form of DNA is characterized by: (A) Right-handed helix (B) Left-handed helix (C) Triple helix (D) Parallel strands 26. Which type of bond forms between cysteine residues in proteins? (A) Ionic bond (B) Hydrogen bond (C) Disulfide bond (D) Peptide bond 27. Which is an example of a molecular motor protein? (A) Hemoglobin (B) Actin (C) Kinesin (D) Collagen 28. Enzyme-substrate interactions are often described by the: (A) Fluid mosaic model (B) Lock-and-key model (C) DNA ladder model (D) Electron cloud model 29. The phospholipid bilayer of membranes is stabilized by: (A) Hydrogen bonding only (B) Hydrophobic effect (C) Covalent bonding (D) Metal ions 30. Which experiment demonstrated that DNA is the genetic material? (A) Griffithβs experiment (B) Hershey-Chase experiment (C) Meselson-Stahl experiment (D) Miller-Urey experiment 31. Which amino acid introduces a bend in protein secondary structure due to its cyclic structure? (A) Glycine (B) Proline (C) Tryptophan (D) Serine 32. The binding of oxygen to hemoglobin is an example of: (A) Cooperative binding (B) Non-cooperative binding (C) Covalent bonding (D) Random diffusion 33. Which spectroscopy is best for identifying functional groups in biomolecules? (A) IR spectroscopy (B) NMR spectroscopy (C) UV-Vis (D) Fluorescence 34. Which protein structure level is most affected by denaturation? (A) Primary (B) Secondary (C) Tertiary (D) Quaternary 35. The double helix model of DNA was proposed by: (A) Watson and Crick (B) Franklin and Wilkins (C) Meselson and Stahl (D) Avery and MacLeod 36. Hydrogen bonds in proteins are typically of strength: (A) 1β5 kcal/mol (B) 10β20 kcal/mol (C) 50β100 kcal/mol (D) 200 kcal/mol 37. Which amino acid is achiral? (A) Alanine (B) Glycine (C) Serine (D) Valine 38. Which technique is used to analyze protein secondary structures like Ξ±-helix and Ξ²-sheet content? (A) Circular dichroism (B) SDS-PAGE (C) Electron microscopy (D) PCR 39. In DNA, hydrogen bonds are formed between: (A) Sugar and phosphate groups (B) Nitrogenous bases (C) Phosphate and bases (D) Sugar and bases 40. Which is a structural protein? (A) Actin (B) Myosin (C) Hemoglobin (D) Insulin 41. Protein denaturation usually does not break: (A) Peptide bonds (B) Hydrogen bonds (C) Ionic interactions (D) Hydrophobic interactions 42. NMR spectroscopy is particularly useful for: (A) Small soluble proteins in solution (B) Large protein crystals (C) DNA melting (D) Atomic force microscopy 43. The heme group in hemoglobin binds: (A) COβ (B) Oβ (C) Nβ (D) ATP 44. The stacking of DNA bases contributes to stability via: (A) Hydrophobic interactions (B) Covalent bonds (C) Ionic interactions (D) Metal ions 45. A typical phospholipid molecule is: (A) Hydrophobic only (B) Amphipathic (C) Hydrophilic only (D) Nonpolar 46. The hydrophobic effect is primarily driven by: (A) Ionic forces (B) Entropy increase of water (C) Hydrogen bonding (D) Van der Waals forces only 47. The stability of collagen triple helix is enhanced by: (A) Glycine residues (B) Disulfide bonds (C) Hydrogen bonds and hydroxylated proline (D) Covalent peptide bonds only 48. The energy of hydrogen bonds in biomolecules is weaker than: (A) Covalent bonds (B) Van der Waals interactions (C) Hydrophobic interactions (D) London dispersion forces 49. Cryo-electron microscopy provides: (A) High-resolution images of biomolecules at near-native state (B) Protein denaturation profiles (C) Molecular weights of proteins (D) Diffusion constants 50. DNA replication is: (A) Conservative (B) Semi-conservative (C) Dispersive (D) Random Molecular Biophysics β MCQsCellular Biophysics β MCQsMembrane Biophysics β MCQsNeurobiophysics β MCQsRadiation Biophysics β MCQsMedical Biophysics β MCQsComputational Biophysics β MCQsStructural Biophysics β MCQsBiophysical Chemistry β MCQsBioenergetics β MCQsBiomechanics β MCQsSystems Biophysics β MCQsBiomolecular Interactions β MCQsBiophysical Methods & Instrumentation β MCQsQuantum Biophysics β MCQsThermodynamics & Statistical Mechanics in Biology β MCQsBiophysics of Macromolecules β MCQsΒ Electrophysiology β MCQsPhotobiophysics β MCQsNanobiophysics β MCQs