Monosaccharides and Disaccharides

MONOSACCHARIDES AND DISACCHARIDES

Section 1
Relative solubility of Glucose and Galactose

Result of the experiment:

| |Weight of the |The weight of |Water added (g)|Weight of the |The weight of the|Amount of the |The saturation |
| |beaker (g) |the beaker | |magnetic bar |beaker and |sugar added (mg)|points of the |
| | |together with | |(g) |magnetic bar with| |sugars (mg/ml) |
| | |the water (g) | | |saturated | | |
| | | | | |solution (g) | | |
|Glucose |38 |47.82 |9.82 |2.97 |58.3 |58.3 |7510 |
|Galactose |35.04 |44.25 |9.21 |2.99 |49.66 |2420 |262.76 |

Interpretation of the result above:

The saturation point of the sugar depends on bonding between sugar and water molecules. As we adding the sugar into water and stirred it, the sugar dissolved quickly. It is because the water molecules can interact with the sugar molecule easily by intramolecular hydrogen bond. When keep adding the sugar, they dissolved slowly and some of them are undissolved. It can be explained that the water molecules are not enough to form intermolecular H-bond with sugar molecules. That’s why we need to stir the solution. It can help the water molecules to form intramolecular H-bond with sugar molecules easily. The sugar can dissolve finally and there no more sugar can be dissolved when saturation point is reached.

The saturation point of the glucose is higher than that of the galactose. Both glucose and galactose are