A five or six carbon sugar is normally found as the ring form. This has two stereoisomers at the anomeric carbon, labelled $ alpha$ (alpha) and $ beta$ (beta). These are in equilibrium, and the conversion from the alpha form to the beta form (and vice versa) is called:

CLASSIFICATION OF CARBOHYDRATES

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Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

A five or six carbon sugar is normally found as the ring form. This has two stereoisomers at the anomeric carbon, labelled

A	acetal formation
B	anomerisation
C	epimerisation
D	mutarotation
E	racemisation

Explanation:

Detailed explanation-1: -Five and six-membered rings are favored over other ring sizes because of their low angle and eclipsing strain. Cyclic structures of this kind are termed furanose (five-membered) or pyranose (six-membered), reflecting the ring size relationship to the common heterocyclic compounds furan and pyran shown on the right.

Detailed explanation-2: -Sugars with four, five or six carbon atoms are termed tetroses, pentoses or hexoses respectively.

Detailed explanation-3: - (Alpha) – the name given to the configuration of a cyclic sugar where the oxygen on the anomeric carbon is on the opposite face of the ring relative to the substituent on the other carbon flanking the ring oxygen.

Detailed explanation-4: -The alpha () anomer of D-glucose has a specific rotation of +112 degrees in water. The beta () anomer of D-glucose has a specific rotation of +19 degrees. (18.7 actually, but rounding up to 19).

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BIOMOLECULES AND ENZYMES

BIOLOGY

CLASSIFICATION OF CARBOHYDRATES