The correct statements are: A. Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis. B. During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact. C. Nucleotides are joined together by glycosidic linkage between textC_1$\text{C}_1$ and textC_4$\text{C}_4$ carbons of the pentose sugar. D. Quaternary structure of proteins represents overall folding of the polypeptide chain. Choose the correct answer from the options given below:

### Core Logic - A is correct: Enzymes lower activation energy significantly. - B is correct: Denaturation affects secondary and tertiary structures while primary structure remains intact. - C is incorrect: Nucleotides are joined by phosphodiester linkages, and glycosidic linkages connect bases to sugars. - D is incorrect: Quaternary structure represents aggregation of multiple polypeptide subunits, not single chain folding. ### Step 1: Final Conclusion Only statements A and B are correct, matching option (3). ### Pattern Recognition Sees: Biomolecules structural and enzymatic properties. Trap: Confusing primary structure disruption with denaturation. ### Chapter Mix Class 12 Chemistry: Biomolecules