Monosaccharides - Definition, Glucose, Fructose, Structure of Glucose and Fructose & Lobry de Bruyn-van Ekenstein Rearrangement Reaction Look at this picture. Have you ever seen this at your home or at shops or in TV ads? Of course yes. Have you ever drunk it? Of course yes. Each one of us has had Glucon D. But what does it do? Why do we drink it, especially in the summer? Why do we start feeling energetic after having it? As it contains 99.4% glucose which is the most common monosaccharide ... Monosaccharides are single sugar molecules that are the basic units of carbohydrates. They are simple sugars with a variety of structures and functions in Monosaccharides are polyhydric aldehydes and ketones that cannot be hydrolyzed into simple carbohydrates. Monosaccharides with aldehyde group (-CHO) are called aldoses while monosaccharides with ketonic group (C=0) are called ketoses. For example, glucose, fructose, ribose, etc. Question 3: Explain what is meant by the pyranose structure of ...