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JEE Main · 2020 · 03 Sep 2020 · Shift 2 · Biomolecules

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The number of groups present in a tripeptide Asp - Glu - Lys is ____.

Answer: 5

Solution

Count the carbonyl () groups in the tripeptide Asp-Glu-Lys. Joining the three residues takes two peptide bonds, which gives two carbonyls. The C-terminal residue carries a free , one more. The side chains of aspartic acid and of glutamic acid each carry a , adding two more, while lysine's side chain has only an amino group and adds none. Altogether there are carbonyl groups.

JEE Main · 2020 · 03 Sep 2020 · Shift 2 · Integer answer

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