UPSC | Prelims GS | 2026

Chirality, discussed in the context of amino acids and thalidomide, refers to:

  1. The ability of a molecule to absorb all wavelengths of visible light
  2. The existence of non-superimposable mirror-image molecular forms
  3. The conversion of a solid directly into a gas
  4. The arrangement of atoms exclusively in a linear chain

Answer

Correct Answer

The existence of non-superimposable mirror-image molecular forms

Explanation

Chirality is molecular handedness: a chiral molecule and its mirror image cannot be superimposed, producing enantiomeric forms. Light absorption is a spectroscopic property, sublimation is a phase change, and a linear chain describes one possible molecular arrangement. The biological effects of thalidomide illustrate why molecular handedness matters in drugs.

Topics: chemistry, chirality and enantiomers, molecular structure, science and technology