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Which structural feature most directly explains cooperativity in hemoglobin but not in myoglobin?

Which statement about DNA strands is correct?

Which of the following side chains can act as a buffer near physiological pH due to its imidazole group?

Which of the following functional groups is most basic?

The following is an excerpt from a recent scientific publication:“Specific noncovalent interactions that are indicative of attractive, directional intermolecular forces have always been of key interest to medicinal chemists in their search for the ‘glue’ that holds drugs and their targets together. … we survey … three kinds of strong, specific, direct, enthalpy‑driven intermolecular forces, including hydrogen bond, halogen bond and salt bridge, involved in the formation of protein‑ligand complex architecture … biological functions … in conferring affinity and specificity for ligand recognition by host protein.” Which interactions are highlighted here as enthalpy‑driven contributors to affinity and specificity in drug design?

Which of the following is a reversible, weak interaction often involved in enzyme-substrate binding?

Which of the following side chains is both aromatic and capable of hydrogen bonding?

The following is an excerpt from a recent scientific publication:“Partial atomic charges are essential for an accurate description of non‑covalent interactions between drug ligands and the MOR… relative to fentanyl, the presence of the fluorine atom in the compound NFEPP alters the partial atomic charges… fentanyl has an overall larger positive charge of the amine system, which could allow stronger H‑bonding to MOR.” According to the excerpt, how does fentanyl’s protonated amine group aid receptor binding?

Which of the following amino acids has the lowest side chain pKa?

The following is an excerpt from a recent scientific publication:“Because amino acid sequence determines protein structure and structure dictates biochemical function, proteins that share a similar amino acid sequence usually perform similar biochemical functions. Starting with the amino acid sequence of a protein, one can often predict which secondary structural elements… will be present in the protein. It is presently not possible, however, to deduce reliably the three-dimensional folded structure of a protein from its amino acid sequence unless its amino acid sequence is very similar to that of a protein whose three‑dimensional structure is already known. Additional information is required to understand the context in which the biochemical activity is used.” Which statement follows from the excerpt regarding prediction of protein function?