JEE Main 2026 — Biomolecules Question with Solution
JEE Main 2026 (21 January Shift 2)
Question
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 and 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 :
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 and 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 :
Choose an option
Show full solutionCorrect option: A
Correct answer
AA and B Only
Step-by-step explanation
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
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
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Biomolecules chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.
Solve interactively →About this question
This is a previous-year question from JEE Main 2026, covering the Biomolecules chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.