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Biomolecules

Previous year questions with solutions · 2025 – 2026

43Questions
37Papers covered
4.63%Weightage 2026▲ 4.8% vs last year
Year-wise statistics questions · papers · average per paper · weightage
YearQuestionsPapersAvg / paperWeightage
202622191.24.63% ▲ 4.8% vs last year
202521191.14.42%

34 questions · newest paper first · page 1 of 2

Ques. 1JEE Main 2026, 8 April (Evening Shift)

The incorrect statement from the following with respect to carbohydrates is :

  1. All monosaccharides are reducing sugars.
  2. The monosaccharide units obtained from hydrolysis of oligosaccharides are always the same.
  3. Starch and cellulose are typical examples of polysaccharides, which are very high molecular weight compounds of more than ten monosaccharide units.
  4. Open chain and cyclic structures co-exist at equilibrium that are responsible for certain properties as in the case of D-(+)-glucose.
Ques. 2JEE Main 2026, 8 April (Evening Shift)

Which of the following amino acid will give violet coloured complex with neutral ferric chloride solution?

  1. Threonine
  2. Serine
  3. Tyrosine
  4. Cysteine
Ques. 3JEE Main 2026, 6 April (Evening Shift)

Consider the following reactions. Total number of electrons in the π bonds and lone pair of electrons in the product (X) is : [figure]

  1. 12
  2. 16
  3. 14
  4. 18
Ques. 4JEE Main 2026, 5 April (Morning Shift)

Identify the correct statements. Choose the correct answer from the options given below :

  1. A and B Only
  2. B and C Only
  3. A, B and D Only
  4. A, B and E Only
Ques. 5JEE Main 2026, 5 April (Evening Shift)

Identify the incorrect statement about tertiary structure of proteins.

  1. They can be fibrous or globular in structure.
  2. The main forces that stabilize the structure are hydrogen bonding, disulphide links, van der Waals and electrostatic forces of attraction.
  3. The structure remains intact when exposed to pH changes.
  4. A linear polypeptide chain will convert to a secondary structure and then further folding of the secondary structure will convert to tertiary structure.
Ques. 6JEE 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
Ques. 7JEE 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. 8JEE 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. 9JEE 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. 10JEE 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. 11JEE 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. 12JEE 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. 13JEE 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. 14JEE 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
Ques. 15JEE Main 2026, 22 January (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 false
  2. Both Statement I and Statement II are true
  3. Statement I is true but Statement II is false
  4. Statement I is false but Statement II is true
Ques. 16JEE Main 2026, 21 January (Morning Shift)

Identify the correct statements. Choose the correct answer from the options given below :

  1. C and D Only
  2. A and D Only
  3. C and E Only
  4. B and E Only
Ques. 17JEE Main 2026, 21 January (Evening Shift)

The correct statements are : Choose the correct answer from the options given below :

  1. A, B and D Only
  2. A, C and D Only
  3. B and C Only
  4. A and B Only
Ques. 18JEE Main 2025, 8 April (Evening Shift)

[figure] Choose the correct option for structures of A and B, respectively

  1. [figure] and [figure]
  2. [figure] and [figure]
  3. [figure] and [figure]
  4. [figure] and [figure]
Ques. 19JEE Main 2025, 7 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 false
  2. Statement I is false but Statement II is true
  3. Both Statement I and Statement II are true
  4. Statement I is true but Statement II is false
Ques. 20JEE Main 2025, 7 April (Evening Shift)

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

  1. Statement I is incorrect but Statement II is correct
  2. Both Statement I and Statement II are incorrect
  3. Both Statement I and Statement II are correct
  4. Statement I is correct but Statement II is incorrect
Ques. 21JEE Main 2025, 4 April (Morning Shift)

Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.

  1. NH2-CH2-COOH and NH2- CH3 |CH-COOH
  2. NH2-CH2-COCl and NH3- CH3 |CH-COCl
  3. NH2-CH2-COCl and NH2- CH3 |CH-COOH
  4. NH2-CH2-COOH and NH2- CH3 |CH-COCl
Ques. 22JEE Main 2025, 4 April (Evening Shift)

A dipeptide, "x" on complete hydrolysis gives "y" and "z". "y" on treatment with aq. HNO2 produces lactic acid. On the other hand "z" on heating gives the following cyclic molecule. [figure] Based on the information given, the dipeptide "x" is :

  1. alanine-alanine
  2. valine-glycine
  3. valine-leucine
  4. alanine-glycine
Ques. 23JEE Main 2025, 3 April (Morning Shift)

Which of the following is the correct structure of L-Fructose?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 24JEE Main 2025, 3 April (Evening Shift)

Fat soluble vitamins are: Choose the correct answer from the options given below:

  1. B & C Only
  2. C & D Only
  3. C & E Only
  4. A & B Only
Ques. 25JEE Main 2025, 2 April (Morning Shift)

Identify the correct statement among the following :

  1. All naturally occurring amino acids except glycine contain one chiral centre.
  2. Amino acid, cysteine can easily undergo dimerisation due to the presence of free SH group.
  3. Glutamic acid is the only amino acid that contains a –COOH group at the side chain.
  4. All naturally occurring amino acids are optically active.
Ques. 26JEE Main 2025, 2 April (Evening Shift)

A tetrapeptide, "x" on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in equimolar proportion each. The number of tetrapeptides (sequences) possible involving each of these amino acids is:

  1. 32
  2. 24
  3. 8
  4. 16
Ques. 27JEE Main 2025, 29 January (Evening Shift)

Identify the essential amino acids from below: Choose the correct answer from the options given below:

  1. (A), (C) and (D) only
  2. (C), (D) and (E) only
  3. (A), (C) and (E) only
  4. (B), (C) and (E) only
Ques. 28JEE Main 2025, 28 January (Morning Shift)

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

  1. Statement I is true but Statement II is false
  2. Both Statement I and Statement II are true
  3. Statement I is false but Statement II is true
  4. Both Statement I and Statement II are false
Ques. 29JEE Main 2025, 28 January (Evening Shift)

Identify correct conversion during acidic hydrolysis from the following : Choose the correct answer from the options given below :

  1. (A), (B) and (C) only
  2. (B), (C) and (D) only
  3. (B), (C) and (E) only
  4. (C), (D) and (E) only
Ques. 30JEE Main 2025, 24 January (Morning Shift)

The carbohydrate "Ribose" present in DNA, is Choose the correct answer from the options given below:

  1. A, D and E Only
  2. B, D and E Only
  3. A, C and D Only
  4. A, B and E Only