Quiz - Carbohydrates - 1 | Carbohydrates

A carbohydrate is a biomolecule consisting of carbon, hydrogen and oxygen atoms

Monosaccharides, also called simple sugars, are the simplest form of sugar and the most basic units of carbohydrates: they are aldehydes (aldoses) or ketones (ketoses) that contain at least 2 additional hydroxy groups. Polysaccharides are polymers of monosaccharides.

In nature, the most common configuration of sugars is the D-configuration. This means that the hydroxyl group attached to the chiral carbon farthest from the carbonyl group (C-5 in aldoses and C-4 in ketoses) is on the right side in a Fischer projection.

Oxidation to mono- or dicarboxylic acids:

Ag₂O deprotonates each alcohols forming alkoxides RO^- which reacts with CH₃I in an SN2 reaction

Nature is remarkably conservative in the construction of polysaccharides: the 3 most abundant natural polysaccharides (cellulose, starch and glycogen) are derived from the glucose.

Aldohexoses have four chirality centers, allowing for a total of 16 possible stereoisomers.

A 6-membered ring in monosaccharides is called a pyranose ring, while a 5-membered ring is called a furanose ring.

In the β-anomer, the hydroxyl group from the carbonyl carbon is cis to the CH₂OH group.

Mutarotation is the process by which α- and β-anomers interconvert in solution through an open-chain form.