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Biomolecules

JEE Main 2025 (Online) 7th April Morning ShiftMCQEasy📈 Topic in 13% papers+4−1
Ques. 1JEE 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

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)

Keep practising — Biomolecules

Ques. 2JEE 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. 3JEE 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. 4JEE Main 2025, 4 April (Morning Shift)

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'

Ques. 5JEE 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. 6JEE 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. 7JEE 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. 8JEE 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. 9JEE 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. 10JEE Main 2025, 29 January (Morning Shift)

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)
Ques. 11JEE 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

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