Read the passage carefully and answer the questions.
Carbohydrates such as cane sugar, glucose, starch etc. belong to a class of naturally occurring organic compounds. Structurally these are polyhydroxy aldehydes or ketones or the compounds which produce such units on hydrolysis. Carbohydrates which are sweet in taste are called sugars. Theses sugars can be reducing or non-reducing. Monosaccharides cannot be hydrolyzed to simpler units whereas Oligosaccharides yield two to ten monosaccharide units on hydrolysis. Polysaccharides yield large number of monosaccharide units on hydrolysis. This class of biomolecules is essential for living systems as they serve as storage molecules in plants and animals. In addition, they provide raw materials for important industries like furniture, textiles, paper, lacquers and breweries. Two aldopentose form important constituents of nucleic acids. Carbohydrates are also called saccharides (Greek: sakcharon which means sugar). Sugar which is used in household and in milk also comes under this class of biomolecules.
Sucrose on hydrolysis yields
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Glucose and fructose
Sucrose is a non-reducing disaccharide of glucose and fructose. On hydrolysis with dilute acid or the enzyme invertase it gives an equimolar mixture of D-(+)-glucose and D-(−)-fructose:
\( \displaystyle \underset{\text{sucrose}}{\ce{C12H22O11}} + \ce{H2O} \xrightarrow{\ce{H+}} \underset{\text{D-(+)-glucose}}{\ce{C6H12O6}} + \underset{\text{D-(}-\text{)-fructose}}{\ce{C6H12O6}} \)
The sign in brackets gives the direction of rotation of plane polarised light: (+) for dextrorotatory and (−) for laevorotatory.
So sucrose gives glucose and fructose.
Why the other options are incorrect
Option (2) Two molecules of glucose — Incorrect. Two glucose units are given by maltose, whose two α-D-glucose units are joined by a C1–C4 glycosidic linkage. Sucrose has one glucose and one fructose unit.
Option (3) Glucose and galactose — Incorrect. These are the units of lactose (milk sugar), made of β-D-galactose and β-D-glucose.
Option (4) Galactose and Fructose — Incorrect. Sucrose has no galactose unit; its two units are glucose and fructose.
NCERT (2026-27 edition):
Disaccharides – …
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| – | 26-05 S2 14-05 S2 14-05 S1 | – | – | – |