**Question:** Which of the following is enantiomer

A. L-Glutamine
B. D-Glutamine
C. L-Aspartate
D. D-Aspartate

**Core Concept:** Enantiomers are stereoisomers that are non-superimposable mirror images of each other, meaning they have the same molecular formula and connectivity of atoms but differ in their spatial arrangement or configuration. Enantiomers can have distinct biological effects and may be pharmacologically active or inactive.

**Why the Correct Answer is Right:** D-Glutamine (Option B) is an enantiomer of L-Glutamine (Option A). Enantiomers are chiral molecules that cannot superimpose on each other when viewed from the same side. D-Amino acids, like D-Glutamine, are typically less common in nature compared to L-amino acids like L-Glutamine.

**Why Each Wrong Option is Incorrect:**

**Option C (L-Aspartate):** L-Aspartate is another L-amino acid, not an enantiomer. Enantiomers have the same molecular formula and connectivity, but differ in their spatial arrangement.

**Option D (D-Aspartate):** D-Aspartate is another D-amino acid, not an enantiomer. Enantiomers are chiral molecules that cannot superimpose on each other when viewed from the same side.

**Option D (L-Aspartate):** L-Aspartate is another L-amino acid, not an enantiomer. As mentioned previously, enantiomers differ in their spatial arrangement, while L-Aspartate is an L-amino acid, not an enantiomer.

**Enantiomerism and Chiral molecules:** Enantiomerism is a property of chiral molecules, which are compounds that exist as two non-superimposable mirror images called enantiomers. These enantiomers can have different biological effects and properties, despite having the same molecular formula and connectivity.

**Core Concept (Enantiomerism):** Enantiomers are stereoisomers that occur when a molecule is not achiral (has a plane of symmetry). Enantiomers can have different biological effects and properties, even though they have the same molecular formula and connectivity of atoms.

**Clinical Relevance (Enantiomerism):** Enantiomers may have distinct pharmacological effects. For example, L-Dopa is the active form of dopamine used in the treatment of Parkinson's disease, while D-Dopa is inactive. This is due to their different interactions with chiral receptors in the body.

**Why the Correct Answer is Right:** D-Glutamine (Option D) is an example of a D-amino acid, a type of chiral molecule that differs from L-amino acids like L-Glutamate. Due to their different spatial arrangement, D-Glutamine and L-Glutamate are enantiomers.

**Why Each Wrong Option is Incorrect:**

**Option A (L-Aspartate):** L-Aspartate is an L-amino acid