How many chiral (asymmetric) carbon atoms are present in the open-chain form of D-glucose ()?
Answer and explanation
Correct answer: C.
- Step 1: In the acyclic aldohexose structure of D-glucose, carbon 1 is the carbonyl carbon (, achiral) and carbon 6 is the terminal primary alcohol (, achiral).
- Step 2: Carbons 2, 3, 4, and 5 each have four distinct substituents: , and two different carbon fragments.
- Step 3: Therefore, there are exactly 4 chiral carbon centers (C2, C3, C4, C5) in open-chain D-glucose.
Answer
.
Why not the others: and underestimate the chiral centers; chiral carbons are found in cyclic glucopyranose where the anomeric C1 carbon becomes chiral upon ring closure.
Practise more Biomolecules and polymers.
Free questions with an explanation for every one, and full timed JEE Main mock tests.
More Biomolecules and polymers questions
- Why is sucrose classified as a non-reducing disaccharide sugar?
- The spontaneous change in the specific optical rotation of a freshly prepared aqueous solution of an optically active sugar until it reaches…
- What type of glycosidic linkage connects the repeating -D-glucose units in the linear structural polysaccharide cellulose?
- Which of the following amino acids is optically INACTIVE because its -carbon is achiral (bonded to two identical hydrogen atoms)?
- In an aqueous solution at its characteristic isoelectric point (pI), an -amino acid exists predominantly as which electrical species…
- Which level of protein structural organization remains COMPLETELY intact and undamaged when a globular protein is subjected to chemical or t…