1, their molecular formulas are different. The molecular formula of sucrose is C 12H22O 1 1, while the molecular formula of glucose is C6H 12O6. This means that their chemical structures are different, so they cannot be regarded as isomers.

2. Their chemical properties are also different. Sucrose is a disaccharide, which is composed of two monosaccharide molecules, glucose and fructose, connected by glycosidic bonds. Therefore, sucrose is a stable compound. In contrast, glucose is a monosaccharide and a simpler sugar molecule. Because of their different molecular structures, their chemical properties are also different.

3. Their uses in organisms are also different. Sucrose is a common sweetener, which is widely used in food and beverage. However, glucose is an important energy source and metabolic intermediate in life. Therefore, in organisms, the role of glucose is far more important than sucrose.

4. Their uses in food and medical fields are also different. Sucrose is a high-energy sweetener, and excessive intake will lead to health problems such as obesity. Therefore, it is necessary to control the intake of sucrose in diet. In contrast, glucose plays an important role in the medical field.

Identification method of sucrose and glucose:

1. Appearance observation: it can be preliminarily identified by observing its appearance. Glucose is a colorless crystal with sweet taste; Sucrose is a white crystal with sweet taste. On the other hand, starch is a white powder with no sweetness. It can be preliminarily distinguished from the appearance.

2. Conduct solubility test: solubility test can be conducted. When these three substances are added to water respectively, both glucose and sucrose can be dissolved in water to form a transparent solution. However, starch is not easy to dissolve in cold water and will form turbid liquid. They can be further identified by solubility test.

3. Using chemical reaction: chemical reaction can be used for identification. For example, iodine solution can be used for identification. When iodine solution is dropped into the solution of glucose, sucrose and starch, the solution of glucose and sucrose will not change, but the solution of starch will turn blue-black. This is because starch forms a complex with iodine, which leads to color change. They can be identified more accurately through chemical reactions.