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Biomolecules · Question 15

JEE Main 2026 (Online) 28th January Evening ShiftMCQEasy📈 Topic in 16% papers+4−1
1

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

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

Answer

(1) [figure]

Solution

A sugar is reducing when it has a free hemiacetal/hemiketal –OH (free anomeric carbon).

(1) Sucrose: C1 of α-D-glucose is linked to C2 of β-D-fructose, so both anomeric carbons are used in the glycosidic bond no free anomeric –OH non-reducing.

(2) Maltose (α-1,4 link), (3) cellobiose (β-1,4 link) and (4) lactose (β-D-galactose C1 to C4 of glucose): the C1 –OH of the second glucose unit is free reducing sugars.

Answer: (1)

JEE Main 2026 (Online) 28th January Evening Shift

Keep practising — Biomolecules

2

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
3

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
4

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
5

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
JEE Main 2026 (Online) 22nd January Morning Shift
6

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

  1. A-IV, B-III, C-II, D-I
  2. A-I, B-III, C-IV, D-II
  3. A-III, B-I, C-IV, D-II
  4. A-IV, B-I, C-II, D-III
JEE Main 2026 (Online) 22nd January Evening Shift
7

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
JEE Main 2026 (Online) 21st January Morning Shift
8

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
9

[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
10

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
11

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

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