NCERT · Class 12 · Chemistry · BiomoleculesDefine carbohydrates and classify them based on their behavior on hydrolysis into three major categories. Give one example of each.

Carbohydrates are optically active polyhydroxy aldehydes or polyhydroxy ketones, or substances that yield such units on hydrolysis. They are commonly known as saccharides. Based on their behavior on hydrolysis, carbohydrates are classified into three major categories:

1. Monosaccharides: These are carbohydrates that cannot be hydrolyzed further into simpler polyhydroxy aldehyde or ketone units. They are the simplest sugars. Example: Glucose or Fructose.

2. Oligosaccharides: These carbohydrates yield 2 to 10 monosaccharide units on hydrolysis. Depending on the number of units, they are further classified as disaccharides, trisaccharides, etc. Example: Sucrose, which on hydrolysis gives one molecule of glucose and one molecule of fructose.

3. Polysaccharides: These are polymeric carbohydrates formed by joining a large number of monosaccharide units together by glycosidic linkages. They are generally insoluble in water and act as food storage or structural materials. Example: Starch or Cellulose. \nThus, the classification of carbohydrates is deeply rooted in their structural complexity and behavior towards aqueous hydrolysis, which dictates their fundamental biological functions as energy sources and structural supports in living organisms.