NEET Biomolecules PYQ practice sheet

8 previous-year NEET Chemistry questions from Biomolecules, newest papers first. Biomolecules carries 14 of the Chemistry questions in NEET 2020 to 2026, so this is a good place to test yourself after revising the chapter. Marking: +4 correct, −1 wrong.

1. 1.

   RE-NEET 2026

   The correct statement about peptides and proteins is

   • (A)
     In $\alpha$-helices, the polypeptide chain is twisted into a left-handed screw (helix) through intramolecular hydrogen bonds
   • (B)
     Tertiary structure of proteins has two or more polypeptide subunits
   • (C)
     Only the proteins having a quaternary structure are biologically active
   • (D)
     In $\beta$-pleated sheet structures, peptide chains are held together by intermolecular hydrogen bonds
2. 2.

   RE-NEET 2026

   Match the vitamins in List I with their sources in List II List I: A. vitamin A B. vitamin $\mathrm{B_{12}}$ C. vitamin E D. vitamin K List II: I. meat II. sunflower oil III. green leafy vegetables IV. carrots Choose the correct answer from the options given below.

   • (A)
     A-IV, B-II, C-I, D-III
   • (B)
     A-III, B-I, C-IV, D-II
   • (C)
     A-II, B-III, C-IV, D-I
   • (D)
     A-IV, B-I, C-II, D-III
3. 3.

   NEET 2026

   The correct statement with regard to the secondary structure of DNA/RNA is

   • (A)
     DNA possesses a single strand helix structure and contains uracil as one of the four bases
   • (B)
     RNA possesses a single strand helix structure and contains thymine as one of the four bases
   • (C)
     DNA possesses a double strand helix structure and contains thymine as one of the four bases
   • (D)
     RNA possesses a double strand helix structure and contains uracil as one of the four bases
4. 4.

   NEET 2024

   The reagents with which glucose does not react to give the corresponding tests/products are A. Tollens' reagent B. Schiff's reagent C. HCN D. $\mathrm{NH_2OH}$ E. $\mathrm{NaHSO_3}$ Choose the correct options from the given below:

   • (A)
     B and C
   • (B)
     E and D
   • (C)
     B and E
   • (D)
     A and D
5. 5.

   NEET 2023

   Given below are two statements : Statement I : A unit formed by the attachment of a base to $1'$ position of sugar is known as nucleoside. Statement II : When nucleoside is linked to phosphorous acid at $5'$-position of sugar moiety, we get nucleotide. In the light of the above statements, choose the correct answer from the options given below :

   • (A)
     Statement I is false but Statement II is true.
   • (B)
     Both Statement I and Statement II are true.
   • (C)
     Both Statement I and Statement II are false.
   • (D)
     Statement I is true but Statement II is false.
6. 6.

   NEET 2022

   The incorrect statement regarding enzymes is:

   • (A)
     Enzymes are very specific for a particular reaction and substrate.
   • (B)
     Enzymes are biocatalysts.
   • (C)
     Like chemical catalysts enzymes reduce the activation energy of bio processes.
   • (D)
     Enzymes are polysaccharides.
7. 7.

   NEET 2021

   The RBC deficiency is deficiency disease of :

   • (A)
     Vitamin $\mathrm{B_{12}}$
   • (B)
     Vitamin $\mathrm{B_6}$
   • (C)
     Vitamin $\mathrm{B_1}$
   • (D)
     Vitamin $\mathrm{B_2}$
8. 8.

   NEET 2020

   Which of the following is a basic amino acid?

   • (A)
     Serine
   • (B)
     Alanine
   • (C)
     Tyrosine
   • (D)
     Lysine