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Differentiate between the… (Class 12 Chemistry 2026, Q20)

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ChemistryCBSE Class 12 · Board exam 2026, set 56/1/1 · 2 marks · Very short answer

CBSE Class 12 Chemistry 2026: question 20

Set in the CBSE Class 12 board exam of 2026, paper 56/1/1, section B, question 20, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q20 · 2 marks · Very short answerBiomolecules

Differentiate between the following :
(i) Peptide linkage and Glycosidic linkage
(ii) Essential amino acids and Non-essential amino acids

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 56/1/1.

Hints

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

Hint 1

Which biomolecules does each linkage join: amino acids or sugars?

Hint 2

For amino acids, ask whether the body can make them or not.

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. (i) Peptide linkage: an amide bond () formed between the –COOH group of one amino acid and the –NH₂ group of another, with loss of water. It is found in proteins.

    Glycosidic linkage: an oxide (–O–) bridge that joins two monosaccharide units, formed with loss of water. It is found in disaccharides and polysaccharides.

    1 mark

  2. (ii) Essential amino acids cannot be synthesised in the body and must be obtained through the diet (e.g. valine, leucine, lysine).

    Non-essential amino acids can be synthesised in the body (e.g. glycine, alanine).

    1 mark

Answer: (i) Peptide: –CONH– amide bond between amino acids; glycosidic: –O– bond between monosaccharides. (ii) Essential amino acids must come from the diet; non-essential ones are made in the body.

Where the marks are

  • Correct distinction between peptide and glycosidic linkage (1 mark)
  • Correct distinction between essential and non-essential amino acids (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 paper2026 board paper, set 56/1/1: 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.