The correct statements are : Choose the correct answer from the options given below :
- A, B and D Only
- A, C and D Only
- B and C Only
- A and B Only
Answer
(4) A and B Only
Solution
A. True. Enzymes lower the activation energy much more than an acid catalyst. As per NCERT, Ea for acid hydrolysis of sucrose is 107 kJ mol-1, while with the enzyme sucrase it is only 36 kJ mol-1.
B. True. On denaturation (heat, change in pH) the globules unfold and helices uncoil; the 2° and 3° structures are destroyed but the 1° structure (sequence of amino acids) remains intact.
C. False. Nucleotides are joined by phosphodiester linkage between the 5′ and 3′ carbon atoms of the pentose sugar (a glycosidic linkage joins the base to the sugar).
D. False. Overall folding of the polypeptide chain is the tertiary structure; the quaternary structure is the spatial arrangement of the subunits.
Correct statements: A and B only
Answer: (4)