Statement A is correct: Enzymes lower the activation energy barrier for reactions, making enzyme-catalyzed hydrolysis of sucrose have lower activation energy than acid-catalyzed hydrolysis.
Statement B is correct: Denaturation disrupts hydrogen bonds and hydrophobic interactions maintaining secondary and tertiary structures, but the covalent peptide bonds forming the primary structure remain intact.
Statement C is incorrect: Nucleotides are joined by phosphodiester linkages between the 3' and 5' carbons of adjacent sugar molecules, not between C1 and C4. Glycosidic linkages connect the nitrogenous base to the C1 carbon of the sugar.
Statement D is incorrect: Quaternary structure describes the arrangement of multiple polypeptide subunits; tertiary structure represents the overall folding of a single polypeptide chain.
Therefore only A and B are correct