Which one of the following sets of monosaccharides forms sucrose?
- -D-galactopyranose and -D-glucopyranose
- -D-glucopyranose and -D-fructofuranose
- -D-glucopyranose and -D-fructofuranose
- -D-glucopyranose and -D-fructopyranose
Answer
(2) -D-glucopyranose and -D-fructofuranose
Solution
As per NCERT, on hydrolysis sucrose gives D-(+)-glucose and D-(−)-fructose. The two monosaccharide units are joined by a glycosidic linkage between C1 of -D-glucose (pyranose form) and C2 of -D-fructose (furanose form).
Sucrose is formed from -D-glucopyranose and -D-fructofuranose.
Answer: (2)