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Biomolecules · Question 8

JEE Main 2026 (Online) 5th April Evening ShiftMCQMedium📈 Topic in 26% papers+4−1
1

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

  1. Both Statement I and Statement II are true
  2. Both Statement I and Statement II are false
  3. Statement I is true but Statement II is false
  4. Statement I is false but Statement II is true

Answer

(1) Both Statement I and Statement II are true

Solution

Statement I: The two pyranose structures are identical at C-2, C-3, C-4 and C-5 and differ only at C-1 (anomeric carbon):

first – OH below the ring at C-1 = α-D-(+)-glucopyranose; second – OH above the ring at C-1 = β-D-(+)-glucopyranose

⇒ they are anomers ∴ Statement I is true.

Statement II: Open-chain forms:

[figure]

D-glucose has 4 chiral carbons (C-2 to C-5); D-fructose has 3 (C-3 to C-5, since C-2 is C=O).

C-3, C-4 and C-5 have the same configuration in both (that is why both give the same osazone)

∴ Statement II is true.

Answer: (1)

JEE Main 2026 (Online) 5th April Evening Shift

Keep practising — Biomolecules

2

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

  1. Both Statement I and Statement II are true
  2. Both Statement I and Statement II are false
  3. Statement I is true but Statement II is false
  4. Statement I is false but Statement II is true
JEE Main 2026 (Online) 4th April Morning Shift
3

Match the List-I with List-II Choose the correct answer from the options given below :

  1. A-II, B-I, C-IV, D-III
  2. A-IV, B-III, C-II, D-I
  3. A-III, B-IV, C-I, D-II
  4. A-II, B-IV, C-I, D-III
JEE Main 2026 (Online) 4th April Morning Shift
4

A D-aldotetrose on oxidation with concentrated HNO3 resulted in optically inactive dicarboxylic acid. The structure of the D-aldotetrose is:

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
JEE Main 2026 (Online) 4th April Evening Shift
5

Match List - I with List - II.

  1. A-II, B-I, C-III, D-IV
  2. A-IV, B-III, C-II, D-I
  3. A-III, B-IV, C-I, D-II
  4. A-I, B-III, C-II, D-IV
JEE Main 2026 (Online) 2nd April Morning Shift
6

Identify the correct pair having amino acid (A) and the hormone (B) that is iodinated derivative of the amino acid (A). (T and Y represent one letter code for amino acids)

  1. Amino acid (A) - T Hormone (B) - Insulin
  2. Amino acid (A) - T Hormone (B) - Thyroxine
  3. Amino acid (A) - Y Hormone (B) - Thyroxine
  4. Amino acid (A) - Y Hormone (B) - Insulin
JEE Main 2026 (Online) 2nd April Evening Shift
7

In the given pentapeptide, find out an essential amino acid (Y) and the sequence present in the pentapeptide : [figure] Choose the correct answer from the options given below :

  1. arrayll(Y) & (Sequence) \ Serine & Thr-Ser-Asp-Ala-Gly array
  2. arrayll(Y) & (Sequence) \ Serine & Ser-Asp-Thr-Ala-Gly array
  3. arrayll(Y) & (Sequence) \ Threonine & Ser-Thr-Asp-Gly-Ala array
  4. arrayll(Y) & (Sequence) \ Threonine & Thr-Ser-Asp-Gly-Ala array
JEE Main 2026 (Online) 28th January Morning Shift
8

Structures of four disaccharides are given below. Among the given disaccharides, the non-reducing sugar is :

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
JEE Main 2026 (Online) 28th January Evening Shift
9

The number of possible tripeptides formed involving alanine (ala), glycine (gly) and valine (val), where no amino acid has been used more than once is:

  1. 8
  2. 3
  3. 4
  4. 6
JEE Main 2026 (Online) 24th January Evening Shift
10

From the given following (A to D) cyclic structures, those which will not react with Tollens' reagent are: [figure]

  1. A and D
  2. A and B
  3. B and D
  4. B and C
JEE Main 2026 (Online) 23rd January Morning Shift
11

Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of

  1. L-sugar component
  2. D-sugar component
  3. Chiral phosphate unit
  4. Base unit
JEE Main 2026 (Online) 23rd January Evening Shift

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