The correct statements are : Activation energy, protein structure and nucleotide linkage
Q. 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 C₁ and C₄ 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. A, B and D Only
B. A, C and D Only
C. B and C Only
D. A and B Only
Correct Answer: D

Explanation (Concept Clarity)

Statement A: Enzymes are biological catalysts and lower the activation energy significantly compared to ordinary acid catalysis. Hence, this statement is correct.

Statement B: During denaturation, hydrogen bonds and other weak interactions responsible for secondary and tertiary structures are broken. However, peptide bonds (primary structure) remain intact. Hence, this statement is correct.

Statement C: Nucleotides are joined by phosphodiester linkage between C₃′ of one sugar and C₅′ of another sugar, not between C₁ and C₄. Hence, this statement is incorrect.

Statement D: Overall folding of a single polypeptide chain represents tertiary structure. Quaternary structure refers to association of multiple polypeptide chains. Hence, this statement is incorrect.

Correct statements: A and B only

Correct Option: D

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Important for Competitive Exams

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