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Biomolecules · Question 29

JEE Main 2025 (Online) 3rd April Morning ShiftMCQMedium📈 Topic in 26% papers+4−1
1

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]

Answer

(2) [figure]

Solution

D-(−)-Fructose (open chain, Fischer projection): C-1 CH2OH, C-2 C=O, –OH on the left at C-3 and on the right at C-4 and C-5.

L-Fructose is the mirror image (enantiomer) of D-fructose every –OH changes side:

C-3: –OH on the right; C-4 and C-5: –OH on the left.

(The –OH on the lowest stereocentre, C-5, is on the left L-configuration.)

This matches structure (2).

Answer: (2)

JEE Main 2025 (Online) 3rd April Morning Shift

Keep practising — Biomolecules

2

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
3

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
4

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
JEE Main 2025 (Online) 2nd April Evening Shift
5

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

  1. (A)-(II), (B)-(III), (C)-(I), (D)-(IV)
  2. (A)-(III), (B)-(III), (C)-(I), (D)-(IV)
  3. (A)-(IV), (B)-(I), (C)-(III), (D)-(II)
  4. (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
JEE Main 2025 (Online) 29th January Morning Shift
6

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
JEE Main 2025 (Online) 28th January Morning Shift
7

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

  1. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
  2. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
  3. (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
  4. (A)-(IV), (B)-(II), (C)-(I), (D)-(III)
JEE Main 2025 (Online) 28th January Evening Shift
8

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
JEE Main 2025 (Online) 28th January Evening Shift

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