Reducing sugars are those that can reduce Fehling’s solution and Tollens’ reagent. All monosaccharides, whether aldose or ketose, are considered reducing sugars.

Polysaccharides, such as starch, cellulose, and glycogen, yield numerous monosaccharide units upon hydrolysis. They are non-sweet in taste and often referred to as non-sugars, playing essential roles in structural and storage functions.

Oligosaccharides are carbohydrates yielding two to ten monosaccharide units upon hydrolysis. Disaccharides, a common type, produce two monosaccharide units, which may be the same or different. For instance, sucrose hydrolysis yields glucose and fructose, while maltose provides two glucose molecules.

A monosaccharide is a carbohydrate that cannot be further hydrolyzed and represents a polyhydroxy aldehyde or ketone unit. Examples include glucose, fructose, and ribose.

Chemically, carbohydrates are defined as optically active polyhydroxy aldehydes or ketones, or compounds that produce such units on hydrolysis. Sugars like sucrose and lactose, common carbohydrates, are also referred to as saccharides, deriving from the Greek word “sakcharon,” meaning sugar.