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Biomolecules · Question 24

JEE Main 2025 (Online) 7th April Morning ShiftMCQEasy📈 Topic in 16% papers+4−1
1

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

Answer

(2) Statement I is false but Statement II is true

Solution

As per NCERT, sucrose on hydrolysis gives an equimolar mixture of D-(+)-glucose and D-(–)-fructose:

C12H22O11 + H2O C6H12O6 + C6H12O6

Fructose is laevorotatory, D-(–)-fructose, not D-(+). Statement I is false.

Sucrose is dextrorotatory (+66.5 ); after hydrolysis the mixture is laevorotatory, because D-(–)-fructose (-92.4 ) rotates more than D-(+)-glucose (+52.5 ). This change in the sign of rotation is inversion, and the product is called invert sugar. Statement II is true.

Answer: (2)

JEE Main 2025 (Online) 7th April Morning Shift

Keep practising — Biomolecules

2

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
3

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
4

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
5

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
6

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
7

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
8

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
9

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
10

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
11

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

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