Which type of carbohydrate is primarily stored in plant tubers such as sweet potatoes?

In plant tubers, such as sweet potatoes, the primary form of stored carbohydrate is polysaccharides. Polysaccharides are large molecules composed of long chains of monosaccharide units linked together. In the case of sweet potatoes, the main polysaccharide stored is starch, which serves as an energy reserve for the plant. When the plant needs energy, enzymes break down the starch into its monosaccharide components for use.

Starch is particularly advantageous for storage because it is insoluble in water, allowing plants to store large amounts of glucose without affecting cell osmotic pressure. This form of carbohydrate storage is efficient for plants, enabling them to maintain energy reserves that can be mobilized quickly when needed, especially during periods of growth or energy demand.

Monosaccharides, oligosaccharides, and disaccharides, while they do play roles in plant metabolism and energy transport, are not the primary storage form in tubers. Monosaccharides are single units, oligosaccharides are short chains of a few monosaccharides, and disaccharides consist of two monosaccharides linked together. These types are more transient forms of carbohydrates and typically serve different functions within the plant than long-term storage.