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Biomolecules

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

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)

Keep practising — Biomolecules

Ques. 2JEE Main 2026, 4 April (Morning Shift)

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
Ques. 3JEE Main 2026, 4 April (Morning Shift)

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
Ques. 4JEE Main 2026, 4 April (Evening Shift)

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]
Ques. 5JEE Main 2026, 2 April (Morning Shift)

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
Ques. 6JEE Main 2026, 2 April (Evening Shift)

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
Ques. 7JEE Main 2026, 28 January (Morning Shift)

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
Ques. 8JEE Main 2026, 28 January (Evening Shift)

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 9JEE Main 2026, 24 January (Evening Shift)

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
Ques. 10JEE Main 2026, 23 January (Morning Shift)

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
Ques. 11JEE Main 2026, 23 January (Evening Shift)

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

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