Carbohydrates

Carbohydrates are stored as polysaccharides for energy. In plants, they are stored as starch, a polysaccharide made of glucose, found in roots, seeds, and chloroplasts. In animals, carbohydrates are stored as glycogen, also a glucose polysaccharide, mainly in the liver and muscles. Thus, the correct pairing is starch for plants and glycogen for animals, which matches option 4.
Thus, the correct answer is Starch, Glycogen.

- α-D-fructofuranose is the six-membered cyclic form of D-fructose, a monosaccharide. It forms a furanose ring structure and the hydroxyl group at the anomeric carbon (C1) is in the axial position, which makes it α-D-fructofuranose.
- In the options, the structure in (1) is the correct representation of α-D-fructofuranose, showing the furanose ring and the correct orientation of the hydroxyl group at the anomeric carbon.
Thus, the correct answer is (1).

- The –CH OH group is present in glucose as it is an alcohol group. When glucose undergoes conversion to glucose penta acetate, the –OH group of glucose reacts with acetic acid to form acetates, indicating the presence of the –CH OH group in glucose.
- Gluconic acid is formed when glucose is oxidized, where the aldehyde group is oxidized to a carboxylic acid, and it doesn't indicate the presence of the –CH OH group.

- n-Hexane is not directly related to glucose and indicates a complete conversion to a hydrocarbon, so it doesn't reflect the presence of the alcohol group.
- Saccharic acid is formed when glucose is oxidized at both the aldehyde and alcohol groups, but it doesn't specifically indicate the –CH OH group.
Thus, the correct answer is (4) Glucose Glucose penta acetate.

When glucose is oxidized with nitric acid, saccharic acid is formed. This reaction involves the oxidation of both the aldehyde group at the C1 position and the primary alcohol group at the C6 position of the glucose molecule, resulting in the formation of a dicarboxylic acid known as saccharic acid.

This transformation is significant in carbohydrate chemistry as it demonstrates the ability of strong oxidizers to convert aldoses into dicarboxylic acids by oxidizing the terminal functional groups.

Tollens' reagent is reduced by aldehydes and some ketones. Fructose (a ketose) and lactose (a reducing sugar) reduce Tollens' reagent, but sucrose (a non-reducing sugar) and cellulose do not.

A non-reducing sugar is one that does not have a free aldehyde or ketone group capable of acting as a reducing agent.
- Glucose, fructose, and maltose all have free reducing ends that can reduce Tollens' or Benedict's reagent.
- Sucrose, however, is a non-reducing sugar because its glycosidic bond involves the aldehyde group of glucose and the ketone group of fructose, leaving no free reducing group.
Hence, sucrose is a non-reducing sugar.