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Biomolecules · Question 21

JEE Main 2026 (Online) 21st January Morning ShiftMCQEasy📈 Topic in 23% papers+4−1
1

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

Answer

(2) A and D Only

Solution

A. As per NCERT, arginine and tryptophan are essential amino acids (marked * in the table of natural amino acids). Correct.

B. Histidine contains an imidazole ring (a heterocyclic ring) in its side chain. Incorrect.

C. Proline contains a five membered ring (pyrrolidine ring). Incorrect.

D. In glycine, H2N-CH2-COOH, the α-carbon carries two H atoms no chiral centre. Correct.

E. The side chain of cysteine is HS-CH2-; MeS-CH2-CH2- is the side chain of methionine. Incorrect.

A and D only are correct.

Answer: (2)

JEE Main 2026 (Online) 21st January Morning Shift

Keep practising — Biomolecules

2

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
JEE Main 2026 (Online) 21st January Evening Shift
3

[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]
JEE Main 2025 (Online) 8th April Evening Shift
4

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
JEE Main 2025 (Online) 7th April Morning Shift
5

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
JEE Main 2025 (Online) 7th April Evening Shift
6

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
JEE Main 2025 (Online) 4th April Morning Shift
7

The total number of hydrogen bonds of a DNA-double Helix strand whose one strand has the following sequence of bases is . 5'-G-G-C-A-A-A-T-C-G-G-C-T-A-3'

JEE Main 2025 (Online) 4th April Morning Shift
8

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
JEE Main 2025 (Online) 4th April Evening Shift
9

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
JEE Main 2025 (Online) 3rd April Morning Shift
10

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
JEE Main 2025 (Online) 3rd April Evening Shift
11

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.
JEE Main 2025 (Online) 2nd April Morning Shift

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