Sucrose is non sugar .But Maltose and lactose are not. Explain?

Sucrose is non sugar of the aldehydic group of sucroseis bonded so it is non sugar.

SUCROSE = GLUCOSE+FRUCTOSE

where as MALTOSE and LACTOSE havind free aldehydic gruops so these are sugar.

Sucrose is a non-reducing Sugar while Maltose and Lactose are reducing due to the presence of free Aldehydic Functional Group in them. In SUgar the Aldehydic Group of both Glucose and Fructose gets condensed and get involved in a Glycosidic Bond. Hence the Reducing Nature of Sucrose becomes deactivatedand non-function due to absence of any functional group.

Hope it helps 

Cheers!!

Sucrose contain Glocose plus Froctose.  Here Sucrose is non reducing sugsr thats why this is non sugar..............................!

your question is wrong

Maltose and lactose both has reducing ends to them due to a free anomeric carbon. Sucrose''s carbon is not free.

This because sucrose is a disaccharide composed of an aldose and a ketose, the latter of which forms a five member ring (instead of 6) with the sixth carbon hanging off the end of the ring, attached to what would be considered a "free anomeric" carbon.

Maltose and lactose are both composed of two aldoses, which both form 6 member rings and have no carbons attached to the end of either ring

Maltose and lactose both has reducing ends to them due to a free anomeric carbon. Sucrose''s carbon is not
free.
This because sucrose is a disaccharide composed of an aldose and a ketose, the latter of which forms a
five member ring (instead of 6) with the sixth carbon hanging off the end of the ring, attached to what
would be considered a "free anomeric" carbon.
Maltose and lactose are both composed of two aldoses, which both form 6 member rings and have no carbons
attached to the end of either ring.