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Assertion (A) : Proteins… (Class 12 Chemistry 2023, Q15)

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ChemistryCBSE Class 12 · Board exam 2023, set 56/5/1 · 1 mark · Assertion-reason

CBSE Class 12 Chemistry 2023: question 15

Set in the CBSE Class 12 board exam of 2023, paper 56/5/1, section A, question 15, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q15 · 1 mark · Assertion-reasonCompetency-basedBiomolecules

Assertion (A) : Proteins are polymers of -amino acids connected by a peptide bond.
Reason (R) : A tetrapeptide contains 4 amino acids linked by 4 peptide bonds.

  1. (A)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  2. (B)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  3. (C)Assertion (A) is true, but Reason (R) is false.
  4. (D)Assertion (A) is false, but Reason (R) is true.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 56/5/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

n amino acids in a chain need how many links?

Hint 2

Count the bonds between 4 units placed in a row.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. The Assertion is true: proteins are polymers of α-amino acids joined by peptide bonds.

  2. The Reason is false: a tetrapeptide has 4 amino acids linked by 3 peptide bonds, not 4.

    1 mark

Answer: (C)

Where the marks are

  • States A is true and R is false (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Biomolecules, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 56/5/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.