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BCH4024 OC Sp26 E1 Q18: A fibrous protein exhibits high tensile strength and insolubility in water. Structural analysis reveals right-handed α helices forming left-handed supercoiled structures stabilized by disulfide bonds between cysteine residues. Which protein best fits this description?

BCH4024 OC Sp26 E1 Q24: Two proteins of similar molecular weight but different oligomerization states are separated using size-exclusion chromatography. The dimeric protein elutes earlier than the monomeric protein. Which explanation best accounts for this observation?

BCH4024 OC Sp26 E1 Q45: A disaccharide contains one free anomeric carbon and one anomeric carbon involved in a glycosidic bond. What functional property does this feature have on the disaccharide?

BCH4024 OC Sp26 E1 Q46: A sugar alcohol reacts with an aldehyde group on the same molecule to form a cyclic structure that is stable in aqueous solution. What is the chemical nature of the linkage formed in this first cyclization step?

BCH4024 OC Sp26 E1 Q21: A globular protein folds spontaneously in aqueous solution with an overall negative ΔG. During folding, the conformational entropy of the polypeptide chain decreases, yet folding remains favorable. This apparent contradiction is resolved by considering changes in solvent entropy and enthalpy. Which factor most directly offsets the unfavorable decrease in conformational entropy of the protein chain?

BCH4024 OC Sp26 E1 Q13: A peptide backbone contains three principal torsion angles that define its conformation. Two of these angles are relatively flexible, while one is highly restricted due to peptide bond planarity. What is the name of this angle?

BCH4024 OC Sp26 E1 Q34: HIV protease inhibitors often contain a hydroxyl group that mimics the oxygen of a tetrahedral intermediate. Unlike serine proteases, HIV protease does not form a covalent enzyme–substrate intermediate. Why are the HIV protease inhibitors still highly effective?

BCH4024 OC Sp26 E1 Q27: A muscle cell experiences a sudden drop in intracellular oxygen concentration during intense exercise. Myoglobin responds by releasing bound O₂ to support mitochondrial respiration. This behavior is best explained by myoglobin’s oxygen-binding characteristics. Which property most directly enables this response?

BCH4024 OC Sp26 E1 Q12: A peptide bond typically adopts a trans configuration because it minimizes steric hindrance between adjacent side chains. However, one amino acid increases the likelihood of a cis peptide bond. Which amino acid most commonly stabilizes a cis peptide bond?

BCH4024 OC Sp26 E1 Q7: Long-chain fatty acids contain amphipathic properties and they form micelles in water. The hydrocarbon portion of the fatty acid is protected by a cage of water molecules. The poor solubility of the fatty acid in water is due to unfavorable free-energy changes. Which thermodynamic combination best explains this behavior?