JEE Main 2023 — Biomolecules Question with Solution
From: JEE Main 2023 (Online) 8th April Morning Shift
Question
Sulphur (S) containing amino acids from the following are:
(a) isoleucine (b) cysteine (c) lysine (d) methionine (e) glutamic acid
Choose an option
Show full solutionCorrect option: A
Correct answer
Ab, d
Step-by-step explanation
Isoleucine is an -amino acid that is used in the biosynthesis of proteins. It contains an amino group, an -carboxylic acid group, and a hydrocarbon side chain with a branch. It is classified as a non-polar, uncharged, branchedchain, aliphatic amino acid.
Lysine is an -amino acid that is a precursor to many proteins. It contains an -amino group, an alpha-carboxylic acid group, and a side chain lysyl, classifying it as a basic, charged, aliphatic amino acid. It is encoded by the codons AAA and AAG. Glutamic acid is an amino acid used to form proteins.
Cysteine and methionine are sulphur containing amino acids. Amino acids get linked to one another by peptide bond formation and form a polypeptide chain of proteins. Hence cysteine and methionine are found in several proteins.
(a) isoleucine
(b) cysteine
(c) lysine
(d) methionine
(e) glutamic acid
Lysine is an -amino acid that is a precursor to many proteins. It contains an -amino group, an alpha-carboxylic acid group, and a side chain lysyl, classifying it as a basic, charged, aliphatic amino acid. It is encoded by the codons AAA and AAG. Glutamic acid is an amino acid used to form proteins.
Cysteine and methionine are sulphur containing amino acids. Amino acids get linked to one another by peptide bond formation and form a polypeptide chain of proteins. Hence cysteine and methionine are found in several proteins.
(a) isoleucine
(b) cysteine
(c) lysine
(d) methionine
(e) glutamic acid
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This is a previous-year question from JEE Main 2023, covering the Biomolecules chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.